Prevent only breaking before "?" in conditional expressions.

This is almost always more readable.

Before:
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    ? aaaaaaaaaaaaaaaaaaaaaaaaaaa : aaaaaaaaaaaaaaaaaaaaaaaaaaa;

After:
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    ? aaaaaaaaaaaaaaaaaaaaaaaaaaa
    : aaaaaaaaaaaaaaaaaaaaaaaaaaa;

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175262 91177308-0d34-0410-b5e6-96231b3b80d8