Re-land [DebugInfo] Add debug location to stubs generated by CGDeclCXX and mark them as artificial

Previously, when clang was compiled with -DLLVM_ENABLE_ASSERTIONS=ON, the added tests were displaying:

inlinable function call in a function with debug info must have a !dbg location
  call void @"??1?$c@UB@@@@QEAA@XZ"(%struct.c* @"?f@?1??d@@YAPEAU?$c@UB@@@@XZ@4U2@A")
fatal error: error in backend: Broken module found, compilation aborted!
Stack dump:
0.      Program arguments: <f:\svn\buildninja\bin\clang -cc1 -emit-llvm debug-info-no-location.cpp> -gcodeview -debug-info-kind=limited
1.      <eof> parser at end of file
2.      Per-function optimization

Fixes PR43012

Differential Revision: https://reviews.llvm.org/D66328
diff --git a/clang/test/CodeGenCXX/aix-static-init-debug-info.cpp b/clang/test/CodeGenCXX/aix-static-init-debug-info.cpp
index 1613504..222956a 100644
--- a/clang/test/CodeGenCXX/aix-static-init-debug-info.cpp
+++ b/clang/test/CodeGenCXX/aix-static-init-debug-info.cpp
@@ -16,14 +16,14 @@
 // CHECK: define internal void @__cxx_global_var_init() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR16:[0-9]+]] {
 // CHECK: entry:
 // CHECK:   call void @_ZN1XC1Ev(%struct.X* @v), !dbg ![[DBGVAR19:[0-9]+]]
-// CHECK:   %0 = call i32 @atexit(void ()* @__dtor_v) [[ATTR:#[0-9]+]], !dbg ![[DBGVAR19]]
+// CHECK:   %0 = call i32 @atexit(void ()* @__dtor_v) [[ATTR:#[0-9]+]], !dbg ![[DBGVAR19b:[0-9]+]]
 // CHECK:   ret void, !dbg ![[DBGVAR19]]
 // CHECK: }
 
 // CHECK: define internal void @__dtor_v() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR20:[0-9]+]] {
 // CHECK: entry:
-// CHECK:   call void @_ZN1XD1Ev(%struct.X* @v), !dbg ![[DBGVAR21:[0-9]+]]
-// CHECK:   ret void, !dbg ![[DBGVAR21]]
+// CHECK:   call void @_ZN1XD1Ev(%struct.X* @v), !dbg ![[DBGVAR21b:[0-9]+]]
+// CHECK:   ret void, !dbg ![[DBGVAR21:[0-9]+]]
 // CHECK: }
 
 // CHECK: define internal void @__finalize_v() [[ATTR:#[0-9]+]] !dbg ![[DBGVAR22:[0-9]+]] {
@@ -52,9 +52,11 @@
 // CHECK:   ret void
 // CHECK: }
 
-// CHECK: ![[DBGVAR16]] = distinct !DISubprogram(name: "__cxx_global_var_init", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: 14, type: !{{[0-9]+}}, scopeLine: 14, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
+// CHECK: ![[DBGVAR16]] = distinct !DISubprogram(name: "__cxx_global_var_init", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, type: !{{[0-9]+}}, flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
 // CHECK: ![[DBGVAR19]] = !DILocation(line: 14, column: 3, scope: ![[DBGVAR16]])
-// CHECK: ![[DBGVAR20]] = distinct !DISubprogram(name: "__dtor_v", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: 14, type: !{{[0-9]+}}, scopeLine: 14, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
+// CHECK: ![[DBGVAR19b]] = !DILocation(line: 0, scope: ![[DBGVAR16]])
+// CHECK: ![[DBGVAR20]] = distinct !DISubprogram(name: "__dtor_v", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: 14, type: !{{[0-9]+}}, scopeLine: 14, flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
+// CHECK: ![[DBGVAR21b]] = !DILocation(line: 0, scope: ![[DBGVAR20]])
 // CHECK: ![[DBGVAR21]] = !DILocation(line: 14, column: 3, scope: ![[DBGVAR20]])
 // CHECK: ![[DBGVAR22]] = distinct !DISubprogram(linkageName: "__finalize_v", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: 14, type: !{{[0-9]+}}, scopeLine: 14, flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !{{[0-9]+}}, retainedNodes: !{{[0-9]+}})
 // CHECK: ![[DBGVAR24]] = !DILocation(line: 14, column: 3, scope: ![[DBGVAR22]])
diff --git a/clang/test/CodeGenCXX/debug-info-atexit-stub.cpp b/clang/test/CodeGenCXX/debug-info-atexit-stub.cpp
new file mode 100644
index 0000000..62d81ab
--- /dev/null
+++ b/clang/test/CodeGenCXX/debug-info-atexit-stub.cpp
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -emit-llvm %s -triple x86_64-windows-msvc -gcodeview -debug-info-kind=limited -o - | FileCheck %s

+

+struct a {

+  ~a();

+};

+template <typename b> struct c : a {

+  c(void (b::*)());

+};

+struct B {

+  virtual void e();

+};

+c<B> *d() {

+  static c<B> f(&B::e);

+  return &f;

+}

+

+// CHECK: define internal void @"??__Ff@?1??d@@YAPEAU?$c@UB@@@@XZ@YAXXZ"()

+// CHECK-SAME: !dbg ![[SUBPROGRAM:[0-9]+]] {

+// CHECK: call void @"??1?$c@UB@@@@QEAA@XZ"(%struct.c* @"?f@?1??d@@YAPEAU?$c@UB@@@@XZ@4U2@A"), !dbg ![[LOCATION:[0-9]+]]

+// CHECK: ![[SUBPROGRAM]] = distinct !DISubprogram(name: "`dynamic atexit destructor for 'f'"

+// CHECK-SAME: flags: DIFlagArtificial

+// CHECK: ![[LOCATION]] = !DILocation(line: 0, scope: ![[SUBPROGRAM]])

diff --git a/clang/test/CodeGenCXX/debug-info-destroy-helper.cpp b/clang/test/CodeGenCXX/debug-info-destroy-helper.cpp
new file mode 100644
index 0000000..9e30c76
--- /dev/null
+++ b/clang/test/CodeGenCXX/debug-info-destroy-helper.cpp
@@ -0,0 +1,24 @@
+// RUN: %clang_cc1 -emit-llvm %s -triple x86_64-windows-msvc -gcodeview -debug-info-kind=limited -o - | FileCheck %s

+

+struct b {

+  b(char *);

+  ~b();

+};

+struct a {

+  ~a();

+};

+struct {

+  b c;

+  const a &d;

+} e[]{nullptr, {}};

+

+// CHECK: define internal void @__cxx_global_array_dtor(i8* %0)

+// CHECK-SAME: !dbg ![[SUBPROGRAM:[0-9]+]] {

+// CHECK: arraydestroy.body

+// CHECK: %arraydestroy.elementPast =

+// CHECK-SAME: !dbg ![[LOCATION:[0-9]+]]

+// CHECK: call void @"??1<unnamed-type-e>@@QEAA@XZ"(%struct.anon* %arraydestroy.element)

+// CHECK-SAME: !dbg ![[LOCATION]]

+// CHECK: ![[SUBPROGRAM]] = distinct !DISubprogram(name: "__cxx_global_array_dtor"

+// CHECK-SAME: flags: DIFlagArtificial

+// CHECK: ![[LOCATION]] = !DILocation(line: 0,

diff --git a/clang/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp b/clang/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp
index e3df9ca..ebbd5e5b 100644
--- a/clang/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp
+++ b/clang/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp
@@ -29,25 +29,25 @@
 A FooTpl<T>::sdm_tpl(sizeof(U) + sizeof(T));
 template A FooTpl<int>::sdm_tpl<int>;
 
-// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_var_init",{{.*}} line: 15,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__dtor_glob",{{.*}} line: 15,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_var_init.1",{{.*}} line: 16,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_array_dtor",{{.*}} line: 16,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__dtor_array",{{.*}} line: 16,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__dtor__ZZ3foovE4stat",{{.*}} line: 19,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_var_init",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__dtor_glob",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_var_init.1",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_array_dtor",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__dtor_array",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__dtor__ZZ3foovE4stat",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
 // CHECK-NOKEXT: !DISubprogram({{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
 
 // CHECK-KEXT: !DISubprogram({{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
 
-// CHECK-MSVC: !DISubprogram(name: "`dynamic initializer for 'glob'",{{.*}} line: 15,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-MSVC: !DISubprogram(name: "`dynamic atexit destructor for 'glob'",{{.*}} line: 15,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-MSVC: !DISubprogram(name: "`dynamic initializer for 'array'",{{.*}} line: 16,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-MSVC: !DISubprogram(name: "__cxx_global_array_dtor",{{.*}} line: 16,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-MSVC: !DISubprogram(name: "`dynamic atexit destructor for 'array'",{{.*}} line: 16,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-MSVC: !DISubprogram(name: "`dynamic atexit destructor for 'stat'",{{.*}} line: 19,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "`dynamic initializer for 'glob'",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "`dynamic atexit destructor for 'glob'",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "`dynamic initializer for 'array'",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "__cxx_global_array_dtor",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "`dynamic atexit destructor for 'array'",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "`dynamic atexit destructor for 'stat'",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
 
 // MSVC does weird stuff when templates are involved, so we don't match exactly,
 // but these names are reasonable.
 // FIXME: These should not be marked DISPFlagLocalToUnit.
-// CHECK-MSVC: !DISubprogram(name: "FooTpl<int>::`dynamic initializer for 'sdm_tpl<int>'",{{.*}} line: 29,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-MSVC: !DISubprogram(name: "FooTpl<int>::`dynamic atexit destructor for 'sdm_tpl<int>'",{{.*}} line: 29,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "FooTpl<int>::`dynamic initializer for 'sdm_tpl<int>'",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "FooTpl<int>::`dynamic atexit destructor for 'sdm_tpl<int>'",{{.*}} flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition
diff --git a/clang/test/CodeGenCXX/debug-info-line.cpp b/clang/test/CodeGenCXX/debug-info-line.cpp
index 951359d..3c09b94 100644
--- a/clang/test/CodeGenCXX/debug-info-line.cpp
+++ b/clang/test/CodeGenCXX/debug-info-line.cpp
@@ -314,7 +314,7 @@
 // CHECK: [[DBG_F9]] = !DILocation(line: 1000,
 // CHECK: [[DBG_F10_STORE]] = !DILocation(line: 1100,
 // CHECK: [[DBG_GLBL_CTOR_B]] = !DILocation(line: 1200,
-// CHECK: [[DBG_GLBL_DTOR_B]] = !DILocation(line: 1200,
+// CHECK: [[DBG_GLBL_DTOR_B]] = !DILocation(line: 0,
 // CHECK: [[DBG_F11]] = !DILocation(line: 1300,
 // CHECK: [[DBG_F12]] = !DILocation(line: 1400,
 // CHECK: [[DBG_F13]] = !DILocation(line: 1500,