Slightly improve formatting of longer pipe statements.

The stronger binding of a string ending in :/= does not really make
sense if it is the only character.

Before:
llvm::outs() << aaaaaaaaaaaaaaaaaaaaaaaa
             << "=" << bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;

After:
llvm::outs() << aaaaaaaaaaaaaaaaaaaaaaaa << "="
             << bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;

llvm-svn: 177075