I think that astore at the start of the exception block is the right pattern to use. I remember some bug about a decompiler choking on no store when it was expected.

org.aspectj.ajdt.core/src/org/aspectj/ajdt/internal/compiler/ast/AspectDeclaration.java

@@ -749,6 +749,7 @@ public class AspectDeclaration extends TypeDeclaration {
 					exc.placeEnd();
 					codeStream.areturn();
 					exc.place();
+					codeStream.astore_1();
 					// this just returns null now - the old version used to throw the caught exception!
 					codeStream.aconst_null();
 					codeStream.areturn();