JVM_IR indy-SAM: use '-Xsam-conversions=indy' if JVM 1.8+, LV 1.5+

compiler/testData/codegen/java9/box/kt36984.kt

@@ -1,4 +1,6 @@
 // TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JVM_IR
+//  ^ JVM_IR back-end generates SAM conversion with invokedynamic
 // WITH_RUNTIME
 
 fun box(): String {
@@ -13,4 +15,4 @@ fun box(): String {
         throw Exception("!samJavaClass.isAnonymousClass(): '${samJavaClass.name}'")
 
     return "OK"
-}
+}