[nfc] [osx] [lldb] Simplify code using GetDebugMapSymfile()

[jankratochvil]

Summary

In D100299 I was not sure what can happen if dwarf_cu.GetOffset() != 0 && GetDebugMapSymfile() as there is:

if (dwarf_cu.GetOffset() == 0 && GetDebugMapSymfile()) {

@clayborg added in 2006-03-30 the part dwarf_cu.GetOffset() == 0 && at this line.
Is this patch simplification OK?

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp

 
 lldb::CompUnitSP SymbolFileDWARF::ParseCompileUnit(DWARFCompileUnit &dwarf_cu) {
   CompUnitSP cu_sp;
   CompileUnit *comp_unit = (CompileUnit *)dwarf_cu.GetUserData();
   if (comp_unit) {
     // We already parsed this compile unit, had out a shared pointer to it
     cu_sp = comp_unit->shared_from_this();
   } else {
-    if (dwarf_cu.GetOffset() == 0 && GetDebugMapSymfile()) {
+    if (GetDebugMapSymfile()) {
+      if (dwarf_cu.GetOffset() != 0) {
+        Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
+        LLDB_LOG(log, "DebugMap cannot address DWARF file CU offset 0x%x",
+                 dwarf_cu.GetOffset());
+        return {};
+      }
       // Let the debug map create the compile unit
       cu_sp = m_debug_map_symfile->GetCompileUnit(this);
       dwarf_cu.SetUserData(cu_sp.get());
     } else {
       ModuleSP module_sp(m_objfile_sp->GetModule());
       if (module_sp) {
         auto initialize_cu = [&](const FileSpec &file_spec,
                                  LanguageType cu_language) {
if (GetDebugMapSymfile()) {
 
         auto lazy_initialize_cu = [&]() {
           // If the version is < 5, we can't do lazy initialization.
           if (dwarf_cu.GetVersion() < 5)
             return false;
 
           // If there is no DWO, there is no reason to initialize
           // lazily; we will do eager initialization in that case.
-          if (GetDebugMapSymfile())
-            return false;
           const DWARFBaseDIE cu_die = dwarf_cu.GetUnitDIEOnly();
           if (!cu_die)
             return false;
           if (!GetDWOName(dwarf_cu, *cu_die.GetDIE()))
             return false;
 
           // With DWARFv5 we can assume that the first support
           // file is also the name of the compile unit. This