[Gardening] Remove unnecessary forward declaration.

dan-zheng · dan-zheng · commit 20dedfb40f52 · 2020-04-09T01:10:47.000-07:00
diff --git a/include/swift/AST/SourceFile.h b/include/swift/AST/SourceFile.h
@@ -20,7 +20,6 @@
 namespace swift {
 
 class PersistentParserState;
-class SynthesizedFileUnit;
 
 /// A file containing Swift source code.
 ///
