Add dg-require-visibility to tests that require visibility support.

	2020-02-29  John David Anglin  <danglin@gcc.gnu.org>

	* /g++.dg/ext/visibility/ref-temp1.C: Require visibility.
	* gfortran.dg/pr90988_4.f: Likewise.
	* gfortran.dg/pr91372.f90: Likewise.

gcc/testsuite/ChangeLog

+2020-02-29  John David Anglin  <danglin@gcc.gnu.org>
+
+	* /g++.dg/ext/visibility/ref-temp1.C: Require visibility.
+	* gfortran.dg/pr90988_4.f: Likewise.
+	* gfortran.dg/pr91372.f90: Likewise.
+
 2020-02-29  Jeff Law  <law@redhat.com>
 
 	* gcc.target/or1k/return-2.c: Update expected output.

gcc/testsuite/g++.dg/ext/visibility/ref-temp1.C

 // PR c++/91476
 // Test that hidden and internal visibility propagates to reference temps.
+// { dg-require-visibility "" }
 
 #define HIDDEN __attribute((visibility("hidden")))
 

gcc/testsuite/gfortran.dg/pr90988_4.f

 c { dg-do compile }
+c { dg-require-visibility "" }
        module foo
           implicit none
           real a,b,c

gcc/testsuite/gfortran.dg/pr91372.f90

 ! { dg-do compile }
+! { dg-require-visibility "" }
 ! PR fortran/91372   
 module module_sf_lake
     implicit none