[PECOFF] Ignore /maxilkfile option.

.ilk file is a file for incremental linking. We don't create nor use
that file.

/MAXILKFILE is an undocumented option to specify the maximum size
of the .ilk file, IIUC. We should just ignore the option.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@222777 91177308-0d34-0410-b5e6-96231b3b80d8