Rename to allow_tsx_tests

This changes skip_tsx_tests to invert the sense, and renames it to
allow_tsx_tests.

gdb/testsuite/gdb.btrace/tsx.exp

@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-require allow_btrace_pt_tests !skip_tsx_tests
+require allow_btrace_pt_tests allow_tsx_tests
 
 standard_testfile .c x86-tsx.S
 if [prepare_for_testing "failed to prepare" $testfile "$srcfile $srcfile2" {debug}] {

gdb/testsuite/lib/gdb.exp

@@ -3649,13 +3649,13 @@ gdb_caching_proc skip_vsx_tests {
     return $skip_vsx_tests
 }
 
-# Run a test on the target to see if it supports TSX hardware.  Return 0 if so,
-# 1 if it does not.  Based on 'check_vmx_hw_available' from the GCC testsuite.
+# Run a test on the target to see if it supports TSX hardware.  Return 1 if so,
+# 0 if it does not.  Based on 'check_vmx_hw_available' from the GCC testsuite.
 
-gdb_caching_proc skip_tsx_tests {
+gdb_caching_proc allow_tsx_tests {
     global srcdir subdir gdb_prompt inferior_exited_re
 
-    set me "skip_tsx_tests"
+    set me "allow_tsx_tests"
 
     # Compile a test program.
     set src {
@@ -3667,7 +3667,7 @@ gdb_caching_proc skip_tsx_tests {
         }
     }
     if {![gdb_simple_compile $me $src executable]} {
-        return 1
+	return 0
     }
 
     # No error message, compilation succeeded so now run it via gdb.
@@ -3680,22 +3680,22 @@ gdb_caching_proc skip_tsx_tests {
     gdb_expect {
         -re ".*Illegal instruction.*${gdb_prompt} $" {
             verbose -log "$me:  TSX hardware not detected."
-            set skip_tsx_tests 1
+	    set allow_tsx_tests 0
         }
         -re ".*$inferior_exited_re normally.*${gdb_prompt} $" {
             verbose -log "$me:  TSX hardware detected."
-            set skip_tsx_tests 0
+	    set allow_tsx_tests 1
         }
         default {
             warning "\n$me:  default case taken."
-            set skip_tsx_tests 1
+	    set allow_tsx_tests 0
         }
     }
     gdb_exit
     remote_file build delete $obj
 
-    verbose "$me:  returning $skip_tsx_tests" 2
-    return $skip_tsx_tests
+    verbose "$me:  returning $allow_tsx_tests" 2
+    return $allow_tsx_tests
 }
 
 # Run a test on the target to see if it supports avx512bf16.  Return 1 if so,