Several platform-wide linker flag variables are defined in
Modules/Platform/<os>.cmake files for C and then copied by the
Modules/CMake<lang>Information.cmake file for each language.
We now use this approach for the variables
CMAKE_EXE_EXPORTS_${lang}_FLAG
CMAKE_SHARED_LIBRARY_SONAME_${lang}_FLAG
CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS
to avoid duplication for multiple languages in each platform file.
This commit creates target and directory properties to enable the Intel
interprocedural optimization support on Linux. Enabling it adds the
compiler option '-ipo' and uses 'xiar' to create archives.
See issue #9615.
The commit "Split Intel compiler information files" moved some Linux
specific flags into the platform-independent Intel compiler info files.
This moves them back.