[PECOFF] Ignore options starting with -?

The compiler is allowed to add a linker option starting with -?<name> to
.drectve section. If the linker can interpret -<name>, it's processed as if
there's no question mark there. If not, such option is silently ignored.

This is a COFF's feature to allow the compiler to emit new linker options
while keeping compatibility with older linkers.

llvm-svn: 189897