[llvm] [LLVM] Automatically strip `-fno-lifetime-dse` from compile_commands.json (PR #124623)

[Michael Kruse via llvm-commits]

Meinersbur wrote:

Just encountered the problem with `CMAKE_CXX_INCLUDE_WHAT_YOU_USE=include-what-you-use`. include-what-you-use use clang internally, so when using gcc as main compiler, the LLVM build system will add `-fno-lifetime-dse` which is rejected by clang/iwyu. This is independent of `compile_commands.json`.

https://github.com/llvm/llvm-project/pull/124623