[clang] [llvm] Reland "[AArch64] Decouple feature dependency expansion. (#94279)" (PR #95231)

[Fangrui Song via cfe-commits]

MaskRay wrote:

@labrinea  @tmatheson-arm

Is this the expected error? zlib uses similar code. 
```
% cat neon.c
#include <arm_neon.h>
__attribute__((target("armv8-a,crc")))
uint64x2_t foo(uint64x2_t a, uint64x2_t b) {
  return veorq_u64(a, b);
}
% newclang --target=aarch64-linux-gnu -c neon.c
neon.c:5:10: error: always_inline function 'veorq_u64' requires target feature 'outline-atomics', but would be inlined into function 'foo' that is compiled without support for 'outline-atomics'
    5 |   return veorq_u64(a, b);
      |          ^
neon.c:5:10: error: always_inline function 'veorq_u64' requires target feature 'v8a', but would be inlined into function 'foo' that is compiled without support for 'v8a'
2 errors generated.
```

https://github.com/llvm/llvm-project/pull/95231