[clang] [ARM] arm_acle.h add Coprocessor Instrinsics (PR #75440)

[David Green via cfe-commits]

davemgreen wrote:

This is the downstream code we have: https://gist.github.com/davemgreen/e7ade833274a60e975e67a66eda7cb44
Note that the __ARM_TARGET_COPROC_XYZ macros are probably wrong. They should be __ARM_FEATURE_COPROC bitfield macros according to the ACLE.

Can you make use of some of that? It would be good to add the macro definition at the same time as the intrinsics (they can be used to control when the intrinsics are available), and the test should be useful for checking they are available at the right times.

https://github.com/llvm/llvm-project/pull/75440