Allow breaking between type and name in for loops.

This fixes llvm.org/PR15033.

Also: Always break before a parameter, if the previous parameter was
split over multiple lines. This was necessary to make the right
decisions in for-loops, almost always makes the code more readable and
also fixes llvm.org/PR14873.

Before:
for (llvm::ArrayRef<NamedDecl *>::iterator I = FD->getDeclsInPrototypeScope()
         .begin(), E = FD->getDeclsInPrototypeScope().end();
     I != E; ++I) {
}
foo(bar(bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb,
        ccccccccccccccccccccccccccccc), d, bar(e, f));

After:
for (llvm::ArrayRef<NamedDecl *>::iterator
         I = FD->getDeclsInPrototypeScope().begin(),
         E = FD->getDeclsInPrototypeScope().end();
     I != E; ++I) {
}
foo(bar(bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb,
        ccccccccccccccccccccccccccccc),
    d, bar(e, f));

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@175741 91177308-0d34-0410-b5e6-96231b3b80d8