[MachO] Add basic support for local symbols.


git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@199155 91177308-0d34-0410-b5e6-96231b3b80d8
Add comment to bit manipulation functions.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@199156 91177308-0d34-0410-b5e6-96231b3b80d8
[PECOFF] Add another test for the module-definition file parser.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@199159 91177308-0d34-0410-b5e6-96231b3b80d8