DebugInfo: Adapt to loss of DITypeRef in LLVM r267296

LLVM stopped using MDString-based type references, and DIBuilder no
longer fills 'retainedTypes:' with every DICompositeType that has an
'identifier:' field.   There are just minor changes to keep the same
behaviour in CFE.

Leaving 'retainedTypes:' unfilled has a dramatic impact on the output
order of the IR though.  There are a huge number of testcase changes,
which were unfortunately not really scriptable.

llvm-svn: 267297
diff --git a/clang/test/CodeGenCXX/debug-info-cxx1y.cpp b/clang/test/CodeGenCXX/debug-info-cxx1y.cpp
index 37f9595..faf29d3 100644
--- a/clang/test/CodeGenCXX/debug-info-cxx1y.cpp
+++ b/clang/test/CodeGenCXX/debug-info-cxx1y.cpp
@@ -1,10 +1,10 @@
 // RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm-only -std=c++14 -emit-llvm -debug-info-kind=limited %s -o - | FileCheck %s
 
 // CHECK: [[EMPTY:![0-9]*]] = !{}
-// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "foo",
+// CHECK: [[FOO:![0-9]+]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "foo",
 // CHECK-SAME:             elements: [[EMPTY]]
 // FIXME: The context of this definition should be the CU/file scope, not the class.
-// CHECK: !DISubprogram(name: "func", {{.*}} scope: !"_ZTS3foo"
+// CHECK: !DISubprogram(name: "func", {{.*}} scope: [[FOO]]
 // CHECK-SAME:          type: [[SUBROUTINE_TYPE:![0-9]*]]
 // CHECK-SAME:          isDefinition: true
 // CHECK-SAME:          declaration: [[FUNC_DECL:![0-9]*]]
@@ -12,7 +12,7 @@
 // CHECK: [[TYPE_LIST]] = !{[[INT:![0-9]*]]}
 // CHECK: [[INT]] = !DIBasicType(name: "int"
 // CHECK: [[FUNC_DECL]] = !DISubprogram(name: "func",
-// CHECK-SAME:                          scope: !"_ZTS3foo"
+// CHECK-SAME:                          scope: [[FOO]]
 // CHECK-SAME:                          type: [[SUBROUTINE_TYPE]]
 // CHECK-SAME:                          isDefinition: false