[clang-format] Correct the AfterControlStatement configuration option output style

[duncan-llvm]

Summary

Due to the order in which the enum cases were defined the old options which were retained for backwards compatibility were being preferred over the new options when printing with the --dump-config option.

I wasn't sure where this stood in regard to tests - I couldn't find anything testing the enum/string conversions in this direction, so if I've missed something please point me in the right direction and I'll add something.

[MyDeveloperDay]

This LGTM, yeah not sure about how this can be tested.

[duncan-llvm]

Based on the New Contributors section I understand I should be asking someone to commit this (and D79022) on my behalf. @MyDeveloperDay would you be able to do that for me or suggest someone else I can ask?

clang/lib/Format/Format.cpp

 };
 
 template <>
 struct ScalarEnumerationTraits<
     FormatStyle::BraceWrappingAfterControlStatementStyle> {
   static void
   enumeration(IO &IO,
               FormatStyle::BraceWrappingAfterControlStatementStyle &Value) {
-    IO.enumCase(Value, "false", FormatStyle::BWACS_Never);
-    IO.enumCase(Value, "true", FormatStyle::BWACS_Always);
     IO.enumCase(Value, "Never", FormatStyle::BWACS_Never);
     IO.enumCase(Value, "MultiLine", FormatStyle::BWACS_MultiLine);
     IO.enumCase(Value, "Always", FormatStyle::BWACS_Always);
+
+    // For backward compatibility.
+    IO.enumCase(Value, "false", FormatStyle::BWACS_Never);
+    IO.enumCase(Value, "true", FormatStyle::BWACS_Always);
   }
 };
 
 template <>
 struct ScalarEnumerationTraits<FormatStyle::BreakConstructorInitializersStyle> {
   static void
   enumeration(IO &IO, FormatStyle::BreakConstructorInitializersStyle &Value) {
     IO.enumCase(Value, "BeforeColon", FormatStyle::BCIS_BeforeColon);