clang-format: Improve line wrapping behavior in call sequences.

r256750 has been leading to an undesired behavior:

  aaaaaaaaaa
      .aaaaaaaaaaaaaaaaaaaaaaaa.aaaaaa(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa);

This change increases penalty for wrapping before member accesses that aren't
calls. Thus, this is again formatted as (as it has been before r256750):

  aaaaaaaaaa.aaaaaaaaaaaaaaaaaaaaaaaa.aaaaaa(
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa);

llvm-svn: 256830