MSVC has a set of qualifiers to allow using 32-bit signed/unsigned
pointers when building 64-bit targets. This is useful for WoW code
(i.e., the part of Windows that handles running 32-bit application on a
64-bit OS). Currently this is supported on x64 using the 270, 271 and
272 address spaces, but does not work for AArch64 at all.
This change adds the same 270, 271 and 272 address spaces to AArch64 and
adjusts the data layout string accordingly. Clang will generate the
correct address space casts, but these will currently be ignored until
the AArch64 backend is updated to handle them.
Partially fixes#62536
This is a resurrected version of <https://reviews.llvm.org/D158857>
(originally created by @a_vorobev) - I've cleaned it up a little, fixed
the rest of the tests and added to auto-upgrade for the data layout.
c9f27275c1