Some headers in LLDB work only when considered as textual inclusion, but not if one attempts to use them on their own or with a different context.
- python-typemaps.h: uses Python definitions without using "Python.h".
- RISCVCInstructions.h uses RISC-V register enums without including the enums header.
- RISCVInstructions.h includes EmulateInstructionRISCV.h, but is unnecessary since we forward-declare EmulateInstructionRISCV anyway. Including the header is problematic because EmulateInstructionRISCV.h uses DecodeResult which isn't defined until later in RISCVInstructions.h.
This makes LLDB build cleanly with the "parse_headers" feature [1]. I'm not sure what the analagous CMake option is.
[1] I didn't find public documentation but @MaskRay wrote this up: https://maskray.me/blog/2022-09-25-layering-check-with-clang#parse_headers
Reviewed By: labath, MaskRay
Differential Revision: https://reviews.llvm.org/D138310
