[NFC][object] Change the input parameter of the method isDebugSection.
Summary: This is a NFC patch to change the input parameter of the method SectionRef::isDebugSection(), by replacing the StringRef SectionName with DataRefImpl Sec. This allows us to determine if a section is debug type in more ways than just by section name.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D102601