[compiler-rt] [compiler-rt] Make Arm builtins aware of endianness (PR #123204)

[Victor Campos via llvm-commits]

vhscampos wrote:

@smithp35 For simplicity I've decided to add support of big endianness to all Arm builtins that have the same pattern (`vmov` between GPRs and double FP).

https://github.com/llvm/llvm-project/pull/123204