Optimize cast gen logic

Author: warunalakshitha

compiler/ballerina-lang/src/main/java/org/wso2/ballerinalang/compiler/bir/codegen/JvmCastGen.java

@@ -1144,9 +1144,6 @@ private void generateCheckCastToJSON(MethodVisitor mv, BType type) {
     private void generateCheckCastToUnionType(MethodVisitor mv, BType sourceType, BUnionType targetType) {
 
         generateCastToAny(mv, sourceType);
-        if (targetType.getMemberTypes().contains(sourceType)) {
-            return;
-        }
         checkCast(mv, sourceType, targetType);
     }