We are going to support DWARF for XCOFF. D95518 is for XCOFF DWARF support of assembly output.
This patch is the NFC part of the patches that are going to support XCOFF DWARF support of object output.
Changes in this patch:
1: Create one base struct XCOFFSection to represent the wrapper of MCSectionXCOFF . The legacy ControlSection now derives from XCOFFSection and the newly created DWARFSection also derives from this struct.
2: Create another base struct SectionEntry to represent the section entry in the section table. The legacy Section now derives from SectionEntry and it is renamed to CsectSectionEntry and the newly created DWARFSectionEntry struct also derives from SectionEntry which will be used to represent DWARF sections.
Usage of the new structs DWARFSection and DWARFSectionEntry will be added later when the NFC patch makes sense to reviewers.