[PS4][DWARF] Explicitly set default DWARF version to 4

GitOrigin-RevId: b8e03be88dc87303f7401ea7b9906947ac67a6db
diff --git a/lib/Driver/ToolChains/PS4CPU.h b/lib/Driver/ToolChains/PS4CPU.h
index 82f9523..4bedaba 100644
--- a/lib/Driver/ToolChains/PS4CPU.h
+++ b/lib/Driver/ToolChains/PS4CPU.h
@@ -80,6 +80,7 @@
     return LangOptions::SSPStrong;
   }
 
+  unsigned GetDefaultDwarfVersion() const override { return 4; }
   llvm::DebuggerKind getDefaultDebuggerTuning() const override {
     return llvm::DebuggerKind::SCE;
   }