[clang] [CIR] Upstream support for emitting constructors (PR #143639)

[Andy Kaylor via cfe-commits]

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@@ -21,6 +21,88 @@
 using namespace clang;
 using namespace clang::CIRGen;
 
+/// Checks whether the given constructor is a valid subject for the
+/// complete-to-base constructor delgation optimization, i.e. emitting the
+/// complete constructor as a simple call to the base constructor.
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andykaylor wrote:

To see this happen from Compiler Explorer, you need to pass `-Xclang -mno-constructor-aliases`. Otherwise, we end up just not emitting the C1 constructor at all in cases where it would call the C2 constructor.

https://github.com/llvm/llvm-project/pull/143639