`CodeGenPassBuilder` is not very tightly coupled to CodeGen, it may need
to reference some method in pass builder in future, so move
`CodeGenPassBuilder.h` to Passes.
The header file has been deprecated since:
commit f09cf34d00625e57dea5317a3ac0412c07292148
Author: Archibald Elliott <archibald.elliott@arm.com>
Date: Tue Dec 20 10:24:02 2022 +0000
In code we use `#include "llvm/Lib/Header.h"` which is located in
"llvm/include/llvm/Lib/Header.h", so we use "llvm/include/" as a header
search path. We should put modulemaps in the same directory and
shouldn't rely on clang to search in immediate subdirectories.
rdar://106677321
Differential Revision: https://reviews.llvm.org/D148776
