Comments and formatting preseving added

idea/testData/intentions/operatorToFunction/keepComments.kt

@@ -0,0 +1,11 @@
+interface C {
+    operator fun set(p1: String, p2: String, value: Int)
+}
+
+class D(val c: C) {
+    fun foo() {
+        this.c/* and this is c */[<caret>
+                "a", // it's "a"
+                "b" /* and this is "b" */] = /* we use 10 */10
+    }
+}