Revert "[libc++] Remap headers in the debug info when building the library (llvm#143004)"

This reverts commit 4d50b40.

There is a discussion on this issue on [1]
I have discussed this on PR and also with developer on IRC, I am
hoping that our position will be considered by 22.x release

[1] llvm#143004

Upstream-Status: Inappropriate [ OE-Specific ]
Signed-off-by: Khem Raj <[email protected]>

Author: kraj

libcxx/include/CMakeLists.txt

@@ -1722,11 +1722,6 @@ add_dependencies(cxx-headers generate-cxx-headers)
 target_include_directories(cxx-headers INTERFACE ${LIBCXX_GENERATED_INCLUDE_TARGET_DIR}
                                                  ${LIBCXX_GENERATED_INCLUDE_DIR})
 
-# Make sure to map the generated include directory back to libc++'s actual source directory when generating
-# debug information. Otherwise, the debug information will refer to generated headers which are created during
-# the build and generally not persistent.
-target_add_compile_flags_if_supported(cxx-headers INTERFACE "-fdebug-prefix-map=${LIBCXX_GENERATED_INCLUDE_DIR}=${LIBCXX_SOURCE_DIR}/include")
-
 if (LIBCXX_INSTALL_HEADERS)
   foreach(file ${files})
     get_filename_component(dir ${file} DIRECTORY)