* Fix linux CMAKE_LIBRARY_ARCHITECTURE_REGEX to support armel-linux-gnueabi.
* Add CMAKE_LIBRARY_ARCHITECTURE_REGEX on kFreeBSD.
* Add CMAKE_LIBRARY_ARCHITECTURE_REGEX on GNU (Hurd).
Also regex is improved to support quadlets. Even if I have not seen this
in the wild yet, reportedly they are possible.
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 is a GNU-specific option that should not be specified for all
compilers on Linux. It tells the GNU compiler to pass -export-dynamic
to the linker to export symbols from executables for use by plugins.
Since we provide the ENABLE_EXPORTS target property to do the same thing
in a cross-platform way, there is no need to pass -rdynamic always.
Since the option is not useful for GNU tools and breaks other tools on
Linux we simply remove it from CMAKE_SHARED_LIBRARY_LINK_<lang>_FLAGS.
This also allows us to stop setting the variable in other Linux compiler
files just to erase the bad flag.
See issue #9985.
