[clang] [Serialization] [ASTWriter] Try to not record namespace as much as possible (PR #179178)

[Shafik Yaghmour via cfe-commits]

================
@@ -4836,11 +4843,8 @@ void ASTWriter::GenerateNameLookupTable(
                                         ModuleLocalTrait);
     }
 
-    auto *ModuleLocalLookups =
-        Chain ? Chain->getModuleLocalLookupTables(DC) : nullptr;
-    ModuleLocalLookupGenerator.emit(
-        ModuleLocalLookupTable, ModuleLocalTrait,
-        ModuleLocalLookups ? &ModuleLocalLookups->Table : nullptr);
+    ModuleLocalLookupGenerator.emit(ModuleLocalLookupTable, ModuleLocalTrait,
+                                    nullptr);
----------------
shafik wrote:

```suggestion
                                    /*Base=*/nullptr);
```

https://github.com/llvm/llvm-project/pull/179178