The grammar for GNU typeof in C requires an expression to be

parenthesized, unlike in C++, e.g.,

  C has: typeof ( expression) 
  C++ has: typeof unary-expression

So, once we've parsed a parenthesized expression after typeof, we
should only go on to parse the postfix expression suffix if we're in
C++. Fixes <rdar://problem/8237491>.

llvm-svn: 109606