PR14918: Don't confuse braced-init-lists after template variable declarations

with function definitions.

We really should remove Parser::isDeclarationAfterDeclarator entirely, since
it's meaningless in C++11 (an open brace could be either a function definition
or an initializer, which is what it's trying to differentiate between). The
other caller of it happens to be correct right now...

llvm-svn: 172510