[clang] [libcxxabi] [clang] respect Ty addrspace when making an alloca (PR #181390)

[Jameson Nash via cfe-commits]

vtjnash wrote:

> You mentioned the ABI IR type, which is computed by the target from the QualType

I'm still not quite following what you're asking. The implementation of the function on main uses the QualType to addrspacecast any indirect (pass-by-pointer) values into the addrspace of the caller, but otherwise addrspacecasts any direct (in register) values into the generic addrspace. The proposal I'm making with this PR is that the addrspace cast should be the same (to the QualType) regardless of the indirect flag on that particular parameter having been set by the ABI.

https://github.com/llvm/llvm-project/pull/181390