[llvm] [DebugInfo][DWARF] Add heapallocsite information (PR #132073)

[Jann Horn via llvm-commits]

thejh wrote:

@dwblaikie Since I don't have commit privileges, can you please land it for me, assuming you don't have objections to how I rebased it?

https://github.com/llvm/llvm-project/pull/132073