[clang] [llvm] [MC] Make UseAssemblerInfoForParsing mostly true (PR #91082)

[Fangrui Song via llvm-commits]

MaskRay wrote:

Removing `getUseAssemblerInfoForParsing` would make MCDwarfFrameEmitter::Emit (for .eh_frame FDE) slow (~4% compile time regression for sqlite3.c amalgamation) due to expensive `AttemptToFoldSymbolOffsetDifference`. For now, make `UseAssemblerInfoForParsing` false in MCDwarfFrameEmitter::Emit.

https://github.com/llvm/llvm-project/pull/91082