Reland (again) D80966 [codeview] Put !heapallocsite on calls to operator new

Check that getDebugInfo() is not null, as in the first revision, before
calling getDebugInfo()->addHeapAllocSiteMetadata().
Else would cause a crash with a new expression in a default arg.

---

Clang marks calls to operator new as heap allocation sites, but the
operator declared at global scope returns a void pointer. There is no
explicit cast in the code, so the compiler has to write down the
allocated type itself.

Also generalize a cast to use CallBase, so that we mark heap alloc sites
when exceptions are enabled.

Differential Revision: https://reviews.llvm.org/D80966
diff --git a/clang/test/CodeGenCXX/debug-info-codeview-heapallocsite.cpp b/clang/test/CodeGenCXX/debug-info-codeview-heapallocsite.cpp
new file mode 100644
index 0000000..33e6038
--- /dev/null
+++ b/clang/test/CodeGenCXX/debug-info-codeview-heapallocsite.cpp
@@ -0,0 +1,38 @@
+// RUN: %clang_cc1 -fexceptions -triple x86_64-windows-msvc -debug-info-kind=limited -gcodeview -fdeclspec -S -emit-llvm %s -o - | FileCheck %s
+
+struct Foo {
+  int x;
+};
+struct Bar {
+  int y;
+};
+extern Foo *gv_foo;
+extern Bar *gv_bar;
+extern "C" void doit() {
+  gv_foo = new Foo();
+  gv_bar = new Bar();
+}
+
+// CHECK-LABEL: define {{.*}}void @doit
+// CHECK: call {{.*}} i8* {{.*}}@"??2@YAPEAX_K@Z"(i64 4) {{.*}} !heapallocsite [[DBG_FOO:!.*]]
+// CHECK: call {{.*}} i8* {{.*}}@"??2@YAPEAX_K@Z"(i64 4) {{.*}} !heapallocsite [[DBG_BAR:!.*]]
+
+extern "C" void useinvoke() {
+  struct HasDtor {
+    ~HasDtor() { delete gv_foo; }
+  } o;
+  gv_foo = new Foo();
+}
+
+// CHECK-LABEL: define {{.*}}void @useinvoke
+// CHECK: invoke {{.*}} i8* {{.*}}@"??2@YAPEAX_K@Z"(i64 4)
+// CHECK-NEXT: to label {{.*}} unwind label {{.*}} !heapallocsite [[DBG_FOO]]
+
+// CHECK: [[DBG_FOO]] = distinct !DICompositeType(tag: DW_TAG_structure_type,
+// CHECK-SAME:                                 name: "Foo"
+// CHECK: [[DBG_BAR]] = distinct !DICompositeType(tag: DW_TAG_structure_type,
+// CHECK-SAME:                                 name: "Bar"
+
+// a new expression in a default arg has caused crashes in the past, add here to test that edge case
+void foo(int *a = new int) {}
+void bar() { foo(); }