[clang] [clang][FatLTO][UnifiedLTO] Pass -enable-matrix to the LTO driver (PR #77829)

[Fangrui Song via cfe-commits]

MaskRay wrote:

The description should mention https://reviews.llvm.org/D153583 ("[ThinLTO][Matrix] Forward -enable-matrix flag to the LTO plugin"). I think this is correct when used in the ThinLTO mode, but it's not clear whether regular LTO mode is correct.

https://github.com/llvm/llvm-project/pull/77829