Rename UseExperimental->OptIn, Experimental->RequiresOptIn in quickfix and IDE tests

idea/testData/quickfix/experimental/basicFunctionContainingClass.kt

@@ -1,8 +1,8 @@
 // "Add '@MyExperimentalAPI' annotation to containing class 'Bar'" "true"
-// COMPILER_ARGUMENTS: -Xuse-experimental=kotlin.Experimental
+// COMPILER_ARGUMENTS: -Xopt-in=kotlin.RequiresOptIn
 // WITH_RUNTIME
 
-@Experimental
+@RequiresOptIn
 annotation class MyExperimentalAPI
 
 @MyExperimentalAPI
@@ -12,4 +12,4 @@ class Bar {
     fun bar() {
         foo<caret>()
     }
-}
+}