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

[David Blaikie via llvm-commits]

dwblaikie wrote:

> The [DWARF v6 working draft](https://snapshots.sourceware.org/dwarfstd/dwarf-spec/latest/dwarf6-20250707-1422.pdf) now contains this feature as `DW_AT_alloc_type` with ID 0x96.
> 
> Which makes me wonder - would you prefer to directly use the ID from the draft standard in LLVM, or would you prefer to use an ID in LLVM-private ID space until the standard is actually finalized?

As unfortunate as it is, I'd prefer to use an LLVM-private ID space until the standard numbering is in a published standard - don't want to risk the complications that would come up if the number was reassigned before the standard ships.

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