[clang] Add isTrivial() and isTriviallyCopyable() AST matchers (PR #90634)

[Ilya Biryukov via cfe-commits]

ilya-biryukov wrote:

I remember back in the day that adding new matchers was a problem because it grew the size of the files beyond some supported compiler's limit.

Could @AaronBallman or someone else knowledgable about this(cc @kadircet) take a look and confirm adding matchers is fine now?

https://github.com/llvm/llvm-project/pull/90634