clang-format: Improve detection of macros annotating functions.

clang-format: Improve detection of macros annotating functions.

Before:
  ASSERT("aaaaaaaaaaaaaaa")
      << aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
      << bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;

After:
  ASSERT("aaaaaaaaaaaaaaa") << aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
                            << bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;

Also cleanup implementation a bit and only mark closing parenthesis of
these annotations.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@237567 91177308-0d34-0410-b5e6-96231b3b80d8