util: improved the check for the existence of the 'buffer' builtin
2to3 is unable to translate '__builtin__' calls to 'builtins' when
hasattr is used (as in hasattr(__builtin__, buffer)). Translating the
check to the format
try:
whatever
except NameError
# define whatever
__builtin__.whatever = whatever
is a correct way of checking for the name and has the benefit of being
translated by 2to3. This patch implements the same idea for the
aforementioned example.