[Gardening] BodyKind::Synthesize implies empty SourceRange

Author: graydon

lib/AST/Decl.cpp

@@ -4593,7 +4593,9 @@ DynamicSelfType *FuncDecl::getDynamicSelfInterface() const {
 
 SourceRange FuncDecl::getSourceRange() const {
   SourceLoc StartLoc = getStartLoc();
-  if (StartLoc.isInvalid()) return SourceRange();
+  if (StartLoc.isInvalid() ||
+      getBodyKind() == BodyKind::Synthesize)
+    return SourceRange();
 
   if (getBodyKind() == BodyKind::Unparsed ||
       getBodyKind() == BodyKind::Skipped)