[Symbolize][PDB] Switch llvm-symbolizer to use PDB_ReaderType::Native.

[akhuang]

Summary

Since native PDB reading has been implemented for symbolizing,
switch to using the native PDB reader by default, unless
LLVM_ENABLE_DIA_SDK is on.

Bug: https://bugs.llvm.org/show_bug.cgi?id=41795

[amccarth]

Fingers crossed...

llvm/lib/DebugInfo/Symbolize/Symbolize.cpp

 //===----------------------------------------------------------------------===//
 
 #include "llvm/DebugInfo/Symbolize/Symbolize.h"
 
 #include "SymbolizableObjectFile.h"
 
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/BinaryFormat/COFF.h"
+#include "llvm/Config/config.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/PDB/PDB.h"
 #include "llvm/DebugInfo/PDB/PDBContext.h"
 #include "llvm/Demangle/Demangle.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Object/MachOUniversal.h"
 #include "llvm/Support/CRC.h"
LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName) {
   // symbolize. Otherwise, use DWARF.
   if (auto CoffObject = dyn_cast<COFFObjectFile>(Objects.first)) {
     const codeview::DebugInfo *DebugInfo;
     StringRef PDBFileName;
     auto EC = CoffObject->getDebugPDBInfo(DebugInfo, PDBFileName);
     if (!EC && DebugInfo != nullptr && !PDBFileName.empty()) {
       using namespace pdb;
       std::unique_ptr<IPDBSession> Session;
-      PDB_ReaderType ReaderType = Opts.UseNativePDBReader
-                                      ? PDB_ReaderType::Native
-                                      : PDB_ReaderType::DIA;
+
+      PDB_ReaderType ReaderType = PDB_ReaderType::Native;
+#if LLVM_ENABLE_DIA_SDK
+      if (!Opts.UseNativePDBReader)
+        ReaderType = PDB_ReaderType::DIA;
+#endif
       if (auto Err = loadDataForEXE(ReaderType, Objects.first->getFileName(),
                                     Session)) {
         Modules.emplace(ModuleName, std::unique_ptr<SymbolizableModule>());
         // Return along the PDB filename to provide more context
         return createFileError(PDBFileName, std::move(Err));
       }
       Context.reset(new PDBContext(*CoffObject, std::move(Session)));
     }