Typo fix
Fix build

As it turns out, the clang sources don’t include TableGen output in the
same way that LLVM does. This was causing header-not-found issues.
Add libclangBasic
Add libclangLex
Fix libclangBasic preprocessor settings

Although this didn’t cause any build issues, it’s still a bit of
messiness I’d rather not have in my codebase.
Add libclangParse