CMake: Build system fixes for XCode. llvm-config still causes us some serious trouble, but it's less serious than it used to be

llvm-svn: 67056

On MSVC 64bits, does not put underscore before the symbol name on the
/INCLUDE linker parameter.

llvm-svn: 62738

and siblings. Support targets whose name does not end on
`CodeGen'. Remove a performance bottleneck.

llvm-svn: 59383

respective asm printers on MSVC.

Based on a patch by Scott Graham.

llvm-svn: 59379

llvm-svn: 59079

llvm-svn: 58485

data manually extracted from llvm-config.

llvm-svn: 58484

llvm-svn: 56540

llvm-svn: 56419