This prevents formattings like this (assuming "parameter" doesn't fit the line):
  bool f = someFunction() && someFunctionWithParam(
      parameter) && someOtherFunction();

Here, "parameter" - the start of line 2 - has a parenthesis level of 2, but
there are subsequent tokens ("&&" and "someOtherFunction") with a lower level.
This is bad for readability as "parameter" hides "someOtherFunction". With this
patch, this changes to:
  bool f = someFunction() &&
           someFunctionWithParam(parameter) &&
           someOtherFunction();

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171038 91177308-0d34-0410-b5e6-96231b3b80d8