[clang] [clang] Sema::isSimpleTypeSpecifier return true for _Bool in c99 (PR #72204)

[Henrik G. Olsson via cfe-commits]

hnrklssn wrote:

There's a dup of `Sema::isSimpleTypeSpecifier` in `FormatToken.cpp` that you may want to update also: `FormatToken::isSimpleTypeSpecifier`. Perhaps that'll make testing easier?

https://github.com/llvm/llvm-project/pull/72204