[clang] [AArch64][ARM] Treat __bf16 as vendor extension type for C++ name mangling substitution (PR #115956)

https://github.com/konstantinschwarz created https://github.com/llvm/llvm-project/pull/115956 This attempts to fix [#115521](https://github.com/llvm/llvm-project/issues/115521). According to the Itanium C++ mangling rules, vendor extended builtin types are considered substitution candidates.

[clang] 6030a07 - Fix hidden-redecls.m test for some environments

Author: Konstantin Schwarz Date: 2020-10-16T09:51:13+02:00 New Revision: 6030a075164c7016b29a67680ed5c9e7c5932109 URL: https://github.com/llvm/llvm-project/commit/6030a075164c7016b29a67680ed5c9e7c5932109 DIFF: https://github.com/llvm/llvm-project/commit/6030a075164c7016b29a67680ed5c9e7c5932109.