[PECOFF] Add /include command line option.

The /include command line option is equivalent to Unix --undefined
option, which forces the linker to resolve the given symbol name
as if it's an unresolved symbol in one of its input files. This feature
is used to link an additional object file or a shared library that no
input files refer to.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@187084 91177308-0d34-0410-b5e6-96231b3b80d8
[PECOFF] Use Windows style options instead of Unix style as primary options.

LLD still accepts both Unix and Windows style options when it's run as
link.exe. This patch does not change functionality.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@187086 91177308-0d34-0410-b5e6-96231b3b80d8