Move InputGraph from Driver to Core. LinkingContext depends on it.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@194641 91177308-0d34-0410-b5e6-96231b3b80d8
[PECOFF] Add missing dependency.

This dependency needs to be cleaned up at some point. .directve handling needs the link.exe option parser.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@194642 91177308-0d34-0410-b5e6-96231b3b80d8
Whitespace.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@194643 91177308-0d34-0410-b5e6-96231b3b80d8