[clang] [CXXNameMangler] Correct the mangling of SVE ACLE types within function names. (PR #69460)

[Paul Walker via cfe-commits]

paulwalker-arm wrote:

To aid review I've split the patch into several commits mainly so the mechanical update of 200+ ACLE tests is separate from the much smaller code changes.  Given this is an ABI break I'd rather land the series as a single commit.

https://github.com/llvm/llvm-project/pull/69460