Rename to allow_btrace_pt_tests

This changes skip_btrace_pt_tests to invert the sense, and renames it
to allow_btrace_pt_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 !skip_btrace_pt_tests !skip_tsx_tests
+require allow_btrace_pt_tests !skip_tsx_tests
 
 standard_testfile .c x86-tsx.S
 if [prepare_for_testing "failed to prepare" $testfile "$srcfile $srcfile2" {debug}] {

gdb/testsuite/lib/gdb.exp

@@ -3852,22 +3852,22 @@ gdb_caching_proc skip_btrace_tests {
 }
 
 # Run a test on the target to see if it supports btrace pt hardware.
-# Return 0 if so, 1 if it does not.  Based on 'check_vmx_hw_available'
+# Return 1 if so, 0 if it does not.  Based on 'check_vmx_hw_available'
 # from the GCC testsuite.
 
-gdb_caching_proc skip_btrace_pt_tests {
+gdb_caching_proc allow_btrace_pt_tests {
     global srcdir subdir gdb_prompt inferior_exited_re
 
-    set me "skip_btrace_tests"
+    set me "allow_btrace_pt_tests"
     if { ![istarget "i?86-*-*"] && ![istarget "x86_64-*-*"] } {
-        verbose "$me:  target does not support btrace, returning 1" 2
-        return 1
+	verbose "$me:  target does not support btrace, returning 1" 2
+	return 0
     }
 
     # Compile a test program.
     set src { int main() { return 0; } }
     if {![gdb_simple_compile $me $src executable]} {
-        return 1
+	return 0
     }
 
     # No error message, compilation succeeded so now run it via gdb.
@@ -3877,32 +3877,32 @@ gdb_caching_proc skip_btrace_pt_tests {
     gdb_reinitialize_dir $srcdir/$subdir
     gdb_load $obj
     if ![runto_main] {
-        return 1
+	return 0
     }
     # In case of an unexpected output, we return 2 as a fail value.
-    set skip_btrace_tests 2
+    set allow_btrace_pt_tests 2
     gdb_test_multiple "record btrace pt" "check btrace pt support" {
         -re "You can't do that when your target is.*\r\n$gdb_prompt $" {
-            set skip_btrace_tests 1
+	    set allow_btrace_pt_tests 0
         }
         -re "Target does not support branch tracing.*\r\n$gdb_prompt $" {
-            set skip_btrace_tests 1
+	    set allow_btrace_pt_tests 0
         }
         -re "Could not enable branch tracing.*\r\n$gdb_prompt $" {
-            set skip_btrace_tests 1
+	    set allow_btrace_pt_tests 0
         }
         -re "support was disabled at compile time.*\r\n$gdb_prompt $" {
-            set skip_btrace_tests 1
+	    set allow_btrace_pt_tests 0
         }
         -re "^record btrace pt\r\n$gdb_prompt $" {
-            set skip_btrace_tests 0
+	    set allow_btrace_pt_tests 1
         }
     }
     gdb_exit
     remote_file build delete $obj
 
-    verbose "$me:  returning $skip_btrace_tests" 2
-    return $skip_btrace_tests
+    verbose "$me:  returning $allow_btrace_pt_tests" 2
+    return $allow_btrace_pt_tests
 }
 
 # Run a test on the target to see if it supports Aarch64 SVE hardware.