Fix a bug that would lead to bad line break decisions in for loops.

Before:
    for (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaa = aaaaaaaaaaaaaaa
             .aaaaaaaaaaaaaaaa;
         aaaaaaaaaaa != aaaaaaaaaaaaaaaaaaa; ++aaaaaaaaaaa) {}

After:
    for (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaa =
             aaaaaaaaaaaaaaa.aaaaaaaaaaaaaaaa;
         aaaaaaaaaaa != aaaaaaaaaaaaaaaaaaa; ++aaaaaaaaaaa) {}

llvm-svn: 173695