[lldb] Switch Section-dumping code to raw_ostream

Also, add a basic test for dumping sections.

lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp

@@ -2957,7 +2957,8 @@ void ObjectFileELF::Dump(Stream *s) {
   s->EOL();
   SectionList *section_list = GetSectionList();
   if (section_list)
-    section_list->Dump(s, nullptr, true, UINT32_MAX);
+    section_list->Dump(s->AsRawOstream(), s->GetIndentLevel(), nullptr, true,
+                       UINT32_MAX);
   Symtab *symtab = GetSymtab();
   if (symtab)
     symtab->Dump(s, nullptr, eSortOrderNone);