Rename skip_vsx_tests to allow form

This renames skip_vsx_tests to allow_vsx_tests and updates it users to
use require.



diff --git a/gdb/testsuite/gdb.arch/powerpc-vsx-gcore.exp b/gdb/testsuite/gdb.arch/powerpc-vsx-gcore.exp
index 6978999..b80afa5 100644
--- a/gdb/testsuite/gdb.arch/powerpc-vsx-gcore.exp
+++ b/gdb/testsuite/gdb.arch/powerpc-vsx-gcore.exp
@@ -18,10 +18,11 @@
 # This test checks that generating and loading a core file preserves
 # the correct VSX register state.
 
-if {![istarget "powerpc*-*-linux*"] || [skip_vsx_tests]} {
+if {![istarget "powerpc*-*-linux*"]} {
     verbose "Skipping PowerPC test for corefiles with VSX registers."
     return
 }
+require allow_vsx_tests
 
 standard_testfile .c
 
diff --git a/gdb/testsuite/gdb.arch/vsx-regs.exp b/gdb/testsuite/gdb.arch/vsx-regs.exp
index b3a120e..e7476f1 100644
--- a/gdb/testsuite/gdb.arch/vsx-regs.exp
+++ b/gdb/testsuite/gdb.arch/vsx-regs.exp
@@ -19,10 +19,11 @@
 #
 
 
-if {![istarget "powerpc*"] || [skip_vsx_tests]} {
+if {![istarget "powerpc*"]} {
     verbose "Skipping vsx register tests."
     return
 }
+require allow_vsx_tests
 
 standard_testfile
 
diff --git a/gdb/testsuite/gdb.arch/vsx-vsr-float28.exp b/gdb/testsuite/gdb.arch/vsx-vsr-float28.exp
index 296a742..0491571 100644
--- a/gdb/testsuite/gdb.arch/vsx-vsr-float28.exp
+++ b/gdb/testsuite/gdb.arch/vsx-vsr-float28.exp
@@ -18,11 +18,11 @@
 # Test the vsr registers print values in float128 bit format.
 #
 
-
-if {![istarget "powerpc*"] || [skip_vsx_tests]} {
+if {![istarget "powerpc*"]} {
     verbose "Skipping vsr float128 field tests."
     return
 }
+require allow_vsx_tests
 
 standard_testfile
 
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 5425ae7..4b8337d 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -3571,19 +3571,19 @@
     return $allow_power_isa_3_1_tests
 }
 
-# Run a test on the target to see if it supports vmx 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 vmx hardware.  Return 1 if so,
+# 0 if it does not.  Based on 'check_vmx_hw_available' from the GCC testsuite.
 
-gdb_caching_proc skip_vsx_tests {
+gdb_caching_proc allow_vsx_tests {
     global srcdir subdir gdb_prompt inferior_exited_re
 
-    set me "skip_vsx_tests"
+    set me "allow_vsx_tests"
 
     # Some simulators are known to not support Altivec instructions, so
     # they won't support VSX instructions as well.
     if { [istarget powerpc-*-eabi] || [istarget powerpc*-*-eabispe] } {
-        verbose "$me:  target known to not support VSX, returning 1" 2
-        return 1
+	verbose "$me:  target known to not support VSX, returning 0" 2
+	return 0
     }
 
     # Make sure we have a compiler that understands altivec.
@@ -3592,8 +3592,8 @@
     } elseif [test_compiler_info xlc*] {
         set compile_flags "additional_flags=-qasm=gcc"
     } else {
-        verbose "Could not compile with vsx support, returning 1" 2
-        return 1
+	verbose "Could not compile with vsx support, returning 0" 2
+	return 0
     }
 
     # Compile a test program containing VSX instructions.
@@ -3609,7 +3609,7 @@
 	}
     }
     if {![gdb_simple_compile $me $src executable $compile_flags]} {
-        return 1
+	return 0
     }
 
     # No error message, compilation succeeded so now run it via gdb.
@@ -3622,22 +3622,22 @@
     gdb_expect {
         -re ".*Illegal instruction.*${gdb_prompt} $" {
             verbose -log "\n$me VSX hardware not detected"
-            set skip_vsx_tests 1
+	    set allow_vsx_tests 0
         }
         -re ".*$inferior_exited_re normally.*${gdb_prompt} $" {
             verbose -log "\n$me: VSX hardware detected"
-            set skip_vsx_tests 0
+	    set allow_vsx_tests 1
         }
         default {
           warning "\n$me: default case taken"
-            set skip_vsx_tests 1
+	    set allow_vsx_tests 0
         }
     }
     gdb_exit
     remote_file build delete $obj
 
-    verbose "$me:  returning $skip_vsx_tests" 2
-    return $skip_vsx_tests
+    verbose "$me:  returning $allow_vsx_tests" 2
+    return $allow_vsx_tests
 }
 
 # Run a test on the target to see if it supports TSX hardware.  Return 1 if so,