[DWARFYAML] make obj2yaml use existing DWARF support for ELF

[haberman]

Summary

These DWARF routines were previously only used for Mach-O.
yaml2obj can handle these DWARF sections, but prior to this
change obj2yaml would not emit them (insted it would just
emit the raw bytes of the .debug_* sections).

[Higuoxing]

As you see, the original DWARF parser is buggy and lacking of tests, so we haven't employed it in elf2yaml. You might need to modify the parser before adding it to elf2yaml. Could you please split this patch into several small patches and add some tests for it? Test cases for DWARF of elf2yaml are in llvm/test/tools/obj2yaml/ELF/DWARF (https://github.com/llvm/llvm-project/tree/main/llvm/test/tools/obj2yaml/ELF/DWARF).

llvm/tools/obj2yaml/elf2yaml.cpp

for (std::unique_ptr<ELFYAML::Chunk> &C : Sections) {
     if (!C->Name.startswith(".debug_"))
       continue;
 
     if (ELFYAML::RawContentSection *RawSec =
             dyn_cast<ELFYAML::RawContentSection>(C.get())) {
       Error Err = Error::success();
       cantFail(std::move(Err));
 
-      if (RawSec->Name == ".debug_aranges")
+      if (RawSec->Name == ".debug_abbrev")
+        dumpDebugAbbrev(*DWARFCtx.get(), DWARF);
+      else if (RawSec->Name == ".debug_addr")
+        Err = dumpDebugAddr(*DWARFCtx.get(), DWARF);
+      else if (RawSec->Name == ".debug_aranges")
         Err = dumpDebugARanges(*DWARFCtx.get(), DWARF);
+      else if (RawSec->Name == ".debug_info")
+        dumpDebugInfo(*DWARFCtx.get(), DWARF);
       else if (RawSec->Name == ".debug_str")
         Err = dumpDebugStrings(*DWARFCtx.get(), DWARF);
       else if (RawSec->Name == ".debug_ranges")
         Err = dumpDebugRanges(*DWARFCtx.get(), DWARF);
-      else if (RawSec->Name == ".debug_addr")
-        Err = dumpDebugAddr(*DWARFCtx.get(), DWARF);
       else
         continue;
 
       // If the DWARF section cannot be successfully parsed, emit raw content
       // instead of an entry in the DWARF section of the YAML.
       if (Err)
         consumeError(std::move(Err));
       else