Bytecode compile is/not is and contains

lynglib/src/commonTest/kotlin/ScriptTest.kt

@@ -5215,6 +5215,20 @@ class ScriptTest {
         assertEquals(ObjFalse, scope.eval("inList(5, [1,2,3])"))
     }
 
+    @Test
+    fun testIsOperatorBytecode() = runTest {
+        val scope = Script.newScope()
+        scope.eval(
+            """
+            fun isInt(x) { x is Int }
+            """.trimIndent()
+        )
+        val disasm = scope.disassembleSymbol("isInt")
+        assertFalse(disasm.contains("not a compiled body"))
+        assertEquals(ObjTrue, scope.eval("isInt(42)"))
+        assertEquals(ObjFalse, scope.eval("isInt(\"42\")"))
+    }
+
     @Test
     fun testFilterBug() = runTest {
         eval(