Fix type annot on method ref in cast ctx

pmd-java/etc/grammar/Java.jjt

@@ -2499,7 +2499,7 @@ private void UnaryExprNotPmStart() #void:
    //  Condensed FIRST set of UnaryExpressionNotPlusMinus
    //  Avoid looking ahead for a whole UnaryExpressionNotPlusMinus, but just for a token
 
-   "~" | "!" | "(" | "switch" | "new" | "this" | "super" | Literal()
+   "~" | "!" | "(" | "switch" | "new" | "this" | "super" | Literal() | "@"
    | <IDENTIFIER>
    | "void" | PrimitiveType()
 }

pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/ast/ASTMethodReferenceTest.kt

@@ -209,6 +209,21 @@ class ASTMethodReferenceTest : ParserTestSpec({
                     it::getTypeArguments shouldBe null
                 }
             }
+
+            // annotated method ref in cast ctx (lookahead trickery)
+            "(Foo) @Vernal Date::getDay" should parseAs {
+                castExpr {
+                    classType("Foo")
+
+                    methodRef(methodName = "getDay") {
+                        classType("Date") {
+                            annotation("Vernal")
+                        }
+
+                        it::getTypeArguments shouldBe null
+                    }
+                }
+            }
         }
     }
 })