Add new diagnostic messages when too many arguments are presented to a
function-like macro.  Clang will attempt to correct the arguments by detecting
braced initializer lists:

1) If possible, suggest parentheses around arguments
containing braced lists which will give the proper number of arguments.
2) If a braced list is detected at the start of a macro argument, it cannot be
corrected by parentheses.  Instead, just point out the location of these
braced lists.