Replace all occurrences of WITH_RUNTIME with WITH_STDLIB

We are going to deprecate `WITH_RUNTIME` directive. The main reason
behind this change is that `WITH_STDLIB` directive better describes
its meaning, specifically it will add kotlin stdlib to test's classpath.

compiler/testData/codegen/box/delegatedProperty/delegateToAnotherCustom.kt

@@ -1,4 +1,4 @@
-// WITH_RUNTIME
+// WITH_STDLIB
 var x: String
     get() = throw Exception("x's getter shouldn't be called")
     set(_) { throw Exception("x's setter shouldn't be called") }