* g++.dg/lto/lto.exp: Add support for C/C++ mix language testing.

	* gcc.dg/lto/pr54625-1_0.c: Move from here...
	* g++.dg/lto/pr54625-1_0.c: ... to here.
	* gcc.dg/lto/pr54625-1_1.C: Likewise.
	* g++.dg/lto/pr54625-1_1.C: Likewise.
	* gcc.dg/lto/pr54625-2_0.c: Likewise.
	* g++.dg/lto/pr54625-2_0.c: Likewise.
	* gcc.dg/lto/pr54625-2_1.C: Likewise.
	* g++.dg/lto/pr54625-2_1.C: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@203862 138bc75d-0d04-0410-961f-82ee72b054a4