Fix parsing error in conditional expressions.

We used to incorrectly parse

aaaaaa ? aaaaaa(aaaaaa) : aaaaaaaa;

Due to an l_paren being followed by a colon, we assumed it to be part of
a constructor initializer. Thus, we never found the colon belonging to
the conditional expression, marked the line as bing incorrect and did
not format it.

llvm-svn: 172621