For a few test cases, clarify dependance on effective-target 'nonlocal_goto' into 'exceptions'

For example, for nvptx, these test cases currently indeed fail with
'sorry, unimplemented: target cannot support nonlocal goto'.  However,
that's just an artefact of non-existing support for exception handling,
and these test cases already require effective-target 'exceptions'.

	gcc/testsuite/
	* gcc.dg/cleanup-12.c: Don't 'dg-skip-if "" { ! nonlocal_goto }'.
	* gcc.dg/cleanup-13.c: Likewise.
	* gcc.dg/cleanup-5.c: Likewise.
	* gcc.dg/gimplefe-44.c: Don't
	'dg-require-effective-target nonlocal_goto'.

gcc/testsuite/gcc.dg/cleanup-12.c

@@ -3,7 +3,6 @@
 /* { dg-do run } */
 /* { dg-options "-O2 -fexceptions" } */
 /* { dg-skip-if "" { "ia64-*-hpux11.*" } } */
-/* { dg-skip-if "" { ! nonlocal_goto } } */
 /* { dg-require-effective-target exceptions } */
 /* Verify unwind info in presence of alloca.  */
 

gcc/testsuite/gcc.dg/cleanup-13.c

@@ -6,7 +6,6 @@
 /* { dg-do run } */
 /* { dg-options "-fexceptions" } */
 /* { dg-skip-if "" { "ia64-*-hpux11.*" } } */
-/* { dg-skip-if "" { ! nonlocal_goto } } */
 /* { dg-require-effective-target exceptions } */
 /* Verify DW_OP_* handling in the unwinder.  */
 

gcc/testsuite/gcc.dg/cleanup-5.c

@@ -2,7 +2,6 @@
 /* { dg-do run } */
 /* { dg-options "-fexceptions" } */
 /* { dg-skip-if "" { "ia64-*-hpux11.*" } } */
-/* { dg-skip-if "" { ! nonlocal_goto } } */
 /* { dg-require-effective-target exceptions } */
 /* Verify that cleanups work with exception handling.  */
 

gcc/testsuite/gcc.dg/gimplefe-44.c

@@ -1,7 +1,6 @@
 /* { dg-do compile } */
 /* { dg-require-effective-target exceptions } */
 /* { dg-options "-fexceptions -fgimple -fdump-tree-eh-eh" } */
-/* { dg-require-effective-target nonlocal_goto } */
 
 void __GIMPLE foo()
 {