Reformat slightly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189630 91177308-0d34-0410-b5e6-96231b3b80d8
Don't bother emitting the pubtypes section on darwin since there aren't
any maintained consumers of it on that platform.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189631 91177308-0d34-0410-b5e6-96231b3b80d8