Preserve newlines before block comments in static initializers.

Summary:
Basically, don't special-case line comments in this regard. And fixed
an incorrect test, that relied on the wrong behavior.

Reviewers: klimek

Reviewed By: klimek

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D962

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183851 91177308-0d34-0410-b5e6-96231b3b80d8