[analyzer][tests][NFC] Add EOF newlines, normalize reference expected files

Reference expected files not ending with a newline are normalized to
have said newlines. Additionally `plist-macros-with-expansion.cpp.plist`
is modified to add a line that is ignored by `%diff_plist`, but not by
the more sensitive pattern proposed by
http://lists.llvm.org/pipermail/cfe-dev/2019-April/061904.html for
`%normalize_plist`.

llvm-svn: 359692