[llvm-branch-commits] [IRTranslator] Handle ptrtoaddr (PR #139601)

[Alexander Richardson via llvm-branch-commits]

https://github.com/arichardson created https://github.com/llvm/llvm-project/pull/139601

We lower ptrtoaddr by emitting a G_PTRTOINT, truncating that to the
address size and then truncate/zext to the final integer type.

This has exposed an issue in the GlobalIsel postlegalizer combines where
the truncate is incorrectly being removed.
See https://github.com/llvm/llvm-project/issues/139598