handle python errmsg changes in {exec,name_forcing}_syntax_error.py

test/tests/exec_syntax_error.py

-
 s = """
 def f():
     a = 1
@@ -11,7 +10,8 @@ f()
 try:
     exec s
 except Exception as e:
-    print repr(e)
+    # avoid microrevision changes to Python error messages
+    print repr(e).replace("because ", "")
 
 s = """
 def f():
@@ -27,4 +27,5 @@ f()
 try:
     exec s
 except Exception as e:
-    print repr(e)
+    # avoid microrevision changes to Python error messages
+    print repr(e).replace("because ", "")

test/tests/name_forcing_syntax_error.py

@@ -208,6 +208,6 @@ for case in cases:
     try:
         exec case
     except SyntaxError as se:
-        print se.message
+        print se.message.replace("because ", "")
         # TODO uncomment this
         # traceback.print_exc()

tools/tester.py

@@ -125,6 +125,8 @@ def canonicalize_stderr(stderr):
             ("AttributeError: '(\w+)' object attribute '(\w+)' is read-only", "AttributeError: \\2"),
             (r"TypeError: object.__new__\(\) takes no parameters", "TypeError: object() takes no parameters"),
             ("IndexError: list assignment index out of range", "IndexError: list index out of range"),
+            (r"unqualified exec is not allowed in function '(\w+)' it (.*)",
+             r"unqualified exec is not allowed in function '\1' because it \2"),
             ]
 
     for pattern, subst_with in substitutions: