[PECOFF] Simplify: Replace two-value enum with bool.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@198634 91177308-0d34-0410-b5e6-96231b3b80d8
Rename parameters to fix shadow warnings.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@198641 91177308-0d34-0410-b5e6-96231b3b80d8