PR fortran/32937

	* trans-array.c (gfc_conv_expr_descriptor): Use
	gfc_conv_const_charlen to generate backend_decl of right type.
	* trans-expr.c (gfc_conv_expr_op): Use correct return type.
	(gfc_build_compare_string): Use int type instead of default
	integer kind for single character comparison.
	(gfc_conv_aliased_arg): Give backend_decl the right type.
	* trans-decl.c (gfc_build_intrinsic_function_decls): Make
	compare_string return an int.

	* gfortran.dg/char_length_6.f90: New test.

	* intrinsics/string_intrinsics.c (compare_string): Return an int.
	* libgfortran.h (compare_string): Likewise.

From-SVN: r127363