Test int128 when -std=f2003

From-SVN: r135347

gcc/testsuite/gfortran.dg/c_kind_int128_test1.f03

+! { dg-do compile }
+! { dg-options "-std=f2003" }
+! { dg-require-effective-target fortran_integer_16 }
+!
+! Note: int_fast*_t currently not supported.
+
+subroutine c_kind_int128_1
+  use, intrinsic :: iso_c_binding
+  implicit none
+
+  integer(c_int128_t) :: a   ! { dg-error "has no IMPLICIT type" }
+  integer(c_int_least128_t) :: b   ! { dg-error "has no IMPLICIT type" }
+! integer(c_int_fast128_t) :: c   
+   
+end subroutine c_kind_int128_1
+
+subroutine c_kind_int128_2
+  use, intrinsic :: iso_c_binding
+
+  integer(c_int128_t) :: a   ! { dg-error "has not been declared or is a variable" }
+  integer(c_int_least128_t) :: b   ! { dg-error "has not been declared or is a variable" }
+! integer(c_int_fast128_t) :: c   
+   
+end subroutine c_kind_int128_2