This patch generalizes the existing code to support CDE intrinsics
which will share some properties with existing MVE intrinsics
(some of the intrinsics will be polymorphic and accept/return values
of MVE vector types).
Specifically the patch:
- Adds new tablegen backends -gen-arm-cde-builtin-def, -gen-arm-cde-builtin-codegen, -gen-arm-cde-builtin-sema, -gen-arm-cde-builtin-aliases, -gen-arm-cde-builtin-header based on existing MVE backends.
- Renames the 'clang_arm_mve_alias' attribute into 'clang_arm_builtin_alias' (it will be used with CDE intrinsics as well as MVE intrinsics)
- Implements semantic checks for the coprocessor argument of the CDE intrinsics as well as the existing coprocessor intrinsics.
- Adds one CDE intrinsic __arm_cx1 to test the above changes