[clang] [Format] Configure ASSIGN_OR_RETURN macros for Google style (PR #169037)

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@@ -967,6 +967,7 @@ TEST(ConfigParseTest, ParsesConfiguration) {
               std::vector<std::string>({"QUNUSED", "QT_REQUIRE_VERSION"}));
 
   CHECK_PARSE_LIST(JavaImportGroups);
+  Style.Macros.clear();
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owenca wrote:

I think `CHECK_PARSE_LIST` is for testing empty lists. Instead, you should add something like the following to line 962 above:
```
  CHECK_PARSE("BasedOnStyle: Google", Macros, std::vector<std::string>({...}));
```

https://github.com/llvm/llvm-project/pull/169037