Migrate all JDK 9 related tests to JDK 11

compiler/testData/codegen/bytecodeText/stringOperations/concatNotDynamic.kt

@@ -1,5 +1,5 @@
 // KOTLIN_CONFIGURATION_FLAGS: STRING_CONCAT=indy-with-constants
-// JVM_TARGET: 9
+// JVM_TARGET: 11
 fun box(a: String, b: String?) {
     val sb = StringBuilder();
     sb.append("123")
@@ -7,4 +7,4 @@ fun box(a: String, b: String?) {
 
 // 0 INVOKEDYNAMIC makeConcatWithConstants
 // 1 append
-// 0 stringPlus
+// 0 stringPlus