testsuite: Add offloading_enabled check and use it for xfail (PR95622)

gcc/testsuite/ChangeLog:

	PR middle-end/95622
	* lib/target-supports.exp (check_effective_target_offloading_enabled):
	New.
	* c-c++-common/goacc/kernels-alias-ipa-pta-2.c: Use it for xfail.
	* c-c++-common/goacc/kernels-alias-ipa-pta-4.c: Likewise.
	* c-c++-common/goacc/kernels-alias-ipa-pta.c: Likewise.

Reviewed-by: Thomas Schwinge <thomas@codesourcery.com>
(cherry picked from commit e70fbee1a3dd9fdeb661366dbf3096d76c4e2d6e)

gcc/testsuite/c-c++-common/goacc/kernels-alias-ipa-pta-2.c

@@ -32,6 +32,7 @@ foo (void)
   free (c);
 }
 
-/* { dg-final { scan-tree-dump-times "(?n)= 0;$" 2 "optimized" } } */
+/* XFAIL: see PR middle-end/95622; fails if ENABLE_OFFLOAD is set.  */
+/* { dg-final { scan-tree-dump-times "(?n)= 0;$" 2 "optimized" { xfail offloading_enabled } } } */
 /* { dg-final { scan-tree-dump-times "(?n)= 1;$" 1 "optimized" } } */
 /* { dg-final { scan-tree-dump-times "(?n)= \\*a" 0 "optimized" } } */

gcc/testsuite/c-c++-common/goacc/kernels-alias-ipa-pta-4.c

@@ -16,6 +16,7 @@ foo (void)
   }
 }
 
-/* { dg-final { scan-tree-dump-times "(?n)= 0;$" 2 "optimized" } } */
+/* XFAIL: see PR middle-end/95622; fails if ENABLE_OFFLOAD is set.  */
+/* { dg-final { scan-tree-dump-times "(?n)= 0;$" 2 "optimized" { xfail offloading_enabled } } } */
 /* { dg-final { scan-tree-dump-times "(?n)= 1;$" 1 "optimized" } } */
-/* { dg-final { scan-tree-dump-times "(?n)= \\*_\[0-9\];$" 0 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "(?n)= \\*_\[0-9\];$" 0 "optimized" { xfail offloading_enabled } } } */

gcc/testsuite/c-c++-common/goacc/kernels-alias-ipa-pta.c

@@ -18,6 +18,7 @@ foo (void)
   }
 }
 
-/* { dg-final { scan-tree-dump-times "(?n)= 0;$" 2 "optimized" } } */
+/* XFAIL: see PR middle-end/95622; fails if ENABLE_OFFLOAD is set.  */
+/* { dg-final { scan-tree-dump-times "(?n)= 0;$" 2 "optimized" { xfail offloading_enabled } } } */
 /* { dg-final { scan-tree-dump-times "(?n)= 1;$" 1 "optimized" } } */
 /* { dg-final { scan-tree-dump-times "(?n)= \\*_\[0-9\]\\\[0\\\];$" 0 "optimized" } } */

gcc/testsuite/lib/target-supports.exp

@@ -998,6 +998,12 @@ proc check_effective_target_fgraphite {} {
     } "-O1 -fgraphite"]
 }
 
+# Return 1 if compiled with --enable-offload-targets=
+# This affects host compilation as ENABLE_OFFLOAD then evaluates to true.
+proc check_effective_target_offloading_enabled {} {
+    return [check_configured_with "--enable-offload-targets"]
+}
+
 # Return 1 if compilation with -fopenacc is error-free for trivial
 # code, 0 otherwise.