Change IsNull and NotNull to use ==/!= nullptr in C++11.
Also update gmock_doctor due to Clang wording change.
diff --git a/scripts/gmock_doctor.py b/scripts/gmock_doctor.py
index e6e6a52..c6a8a90 100755
--- a/scripts/gmock_doctor.py
+++ b/scripts/gmock_doctor.py
@@ -362,7 +362,7 @@
r'which is of non-class type \'(.*::)*(?P<class_name>.+)\*\'')
clang_regex = (_CLANG_FILE_LINE_RE + r'error: member reference type '
r'\'(?P<class_name>.*?) *\' is a pointer; '
- r'maybe you meant to use \'->\'\?')
+ r'(did you mean|maybe you meant) to use \'->\'\?')
diagnosis = """
The first argument to ON_CALL() and EXPECT_CALL() must be a mock *object*,
not a *pointer* to it. Please write '*(%(mock_object)s)' instead of