[clang] [llvm] [RISCV][Zicfilp] Enable Zicfilp CFI compiler behaviors by looking at module flags (PR #152121)

[Ming-Yi Lai via cfe-commits]

mylai-mtk wrote:

Update: Model ZICFILP-func-sig and ZICFILP-unlabeled as real target features

Reason: During my prototyping of some ELF header field emission (cf. riscv-non-isa/riscv-elf-psabi-doc#474), and I found that in the emission function only "real" target features could be accessed, so I think it's better to just consolidate the module flags into real target features. 

https://github.com/llvm/llvm-project/pull/152121