* tree.c (type_with_interoperable_signedness): New.

	* tree.c (type_with_interoperable_signedness): New.
	(gimple_canonical_types_compatible_p): Use it.
	* tree.h (type_with_interoperable_signedness): Declare

	* lto.c (hash_canonical_type): Honor
	type_with_interoperable_signedness.

	* gfortran.dg/lto/bind_c-2_0.f90: New testcase.
	* gfortran.dg/lto/bind_c-2_1.c: New testcase.
	* gfortran.dg/lto/bind_c-3_0.f90: New testcase.
	* gfortran.dg/lto/bind_c-3_1.c: New testcase.
	* gfortran.dg/lto/bind_c-4_0.f90: New testcase.
	* gfortran.dg/lto/bind_c-4_1.c: New testcase.
	* gfortran.dg/lto/bind_c-5_0.f90: New testcase.
	* gfortran.dg/lto/bind_c-5_1.c: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@228680 138bc75d-0d04-0410-961f-82ee72b054a4