Adjust various testData to remove/charAt transformation

compiler/testData/codegen/box/builtinStubMethods/ListWithAllImplementations.kt

@@ -14,7 +14,7 @@ class MyList<T>(val v: T): List<T> {
     override fun equals(other: Any?): Boolean = false
 
     public fun add(e: T): Boolean = true
-    public fun remove(o: Any?): Boolean = true
+    public fun remove(o: T): Boolean = true
     public fun addAll(c: Collection<T>): Boolean = true
     public fun addAll(index: Int, c: Collection<T>): Boolean = true
     public fun removeAll(c: Collection<Any?>): Boolean = true
@@ -22,7 +22,7 @@ class MyList<T>(val v: T): List<T> {
     public fun clear() {}
     public fun set(index: Int, element: T): T = element
     public fun add(index: Int, element: T) {}
-    public fun remove(index: Int): T = v
+    public fun removeAt(index: Int): T = v
 }
 
 fun box(): String {