https://gcc.gnu.org/bugzilla/show_bug.cgi?id=39947
--- Comment #7 from Kai Tietz <ktietz at gcc dot gnu.org> --- Just as note: This issue got partial addressed for 4.8 gcc for cross-compiler version. We place bitness-version into specific lib folder for bitness. Just for native mode - for being compatible with existing build-scenarios of native compiler - we still place target's libgcc's DLL into host's bin-folder. This issue is just present for native multilib-version.
