JVM: CHECK_BYTECODE_TEST directive + use it in INVOKEDYNAMIC tests

compiler/testData/codegen/box/invokedynamic/sam/enhancedNullabilityMix.kt

@@ -1,6 +1,13 @@
 // TARGET_BACKEND: JVM
 // JVM_TARGET: 1.8
 // SAM_CONVERSIONS: INDY
+
+// CHECK_BYTECODE_TEXT
+// JVM_IR_TEMPLATES
+// 0 java/lang/invoke/LambdaMetafactory
+// 1 final class EnhancedNullabilityKt\$box\$t1\$1
+//  TODO check why EnhancedNullabilityKt\$box\$t1\$1 is not synthetic
+
 // FILE: enhancedNullability.kt
 fun interface IGetInt {
     fun get(x: Int): Int