Simplify the driver a bit: Break skip_{if,unless}_tag down into smaller parts

testsuite/driver/testlib.py

@@ -286,19 +286,17 @@ def _namebase( opts, nb ):
 
 # ---
 
-def skip_if_tag( tag ):
-   return lambda opts, t=tag: _skip_if_tag(opts, t)
-
-def _skip_if_tag( opts, tag ):
+def if_tag( tag, f ):
     if tag in config.compiler_tags:
-	opts.skip = 1
-	
-def skip_unless_tag( tag ):
-   return lambda opts, t=tag: _skip_unless_tag(opts, t)
+        return f
+    else:
+        return normal
 
-def _skip_unless_tag( opts, tag ):
+def unless_tag( tag, f ):
     if not (tag in config.compiler_tags):
-	opts.skip = 1
+        return f
+    else:
+        return normal
 
 # ---
 def alone(opts):

testsuite/tests/ghc-regress/esc/all.T

-esc = skip_unless_tag('esc')
+esc = unless_tag('esc', skip)
 
 test('TestList', esc, compile, ['-fesc'])
 test('TestImport', esc, compile, ['-fesc'])