[PECOFF] support additional subsystem identifiers

This completes the subsystem name parsing to support the identifiers that the
Microsoft link.exe linker supports.  "windows" and "console" are left as the
first items as they are the expected common paths.

Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@189181 91177308-0d34-0410-b5e6-96231b3b80d8