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/strings/constInStringTemplate.kt

@@ -1,6 +1,6 @@
 // IGNORE_BACKEND: WASM
 // WASM_MUTE_REASON: Float.toString()
-// WITH_RUNTIME
+// WITH_STDLIB
 
 import kotlin.test.assertEquals
 

compiler/testData/codegen/box/strings/forInString.kt

@@ -1,4 +1,4 @@
-// WITH_RUNTIME
+// WITH_STDLIB
 
 fun foo(): Int {
     var sum = 0

compiler/testData/codegen/box/strings/javaToStringNPE.kt

@@ -1,5 +1,5 @@
 // TARGET_BACKEND: JVM
-// WITH_RUNTIME
+// WITH_STDLIB
 
 // FILE: J.java
 import org.jetbrains.annotations.NotNull;

compiler/testData/codegen/box/strings/kt13213.kt

@@ -1,6 +1,6 @@
 // IGNORE_BACKEND: JVM
 // IGNORE_BACKEND: WASM
-// WITH_RUNTIME
+// WITH_STDLIB
 
 fun box(): String {
     val t = test.trim()

compiler/testData/codegen/box/strings/kt13213a.kt

@@ -1,5 +1,5 @@
 // IGNORE_BACKEND: JVM
-// WITH_RUNTIME
+// WITH_STDLIB
 
 fun Char.hex() = toInt().toString(16)
 

compiler/testData/codegen/box/strings/nestedConcat.kt

@@ -1,4 +1,4 @@
-// WITH_RUNTIME
+// WITH_STDLIB
 
 import kotlin.test.assertEquals
 

compiler/testData/codegen/box/strings/stringFromJavaPlus.kt

@@ -1,5 +1,5 @@
 // TARGET_BACKEND: JVM
-// WITH_RUNTIME
+// WITH_STDLIB
 
 // FILE: J.java
 import org.jetbrains.annotations.NotNull;

compiler/testData/codegen/box/strings/stringPlusOnlyWorksOnString.kt

@@ -1,4 +1,4 @@
-// WITH_RUNTIME
+// WITH_STDLIB
 
 fun box(): String {
     var x: MutableCollection<Int> = ArrayList()

compiler/testData/codegen/box/strings/trimOptimization.kt

@@ -1,4 +1,4 @@
-// WITH_RUNTIME
+// WITH_STDLIB
 // IGNORE_BACKEND: JS
 // IGNORE_BACKEND: WASM