DeprecatedSymbolUsageFix: more correct generation of "let" for safe call

idea/testData/quickfix/deprecatedSymbolUsage/changeThisSafeCallWithValue3Runtime.kt

@@ -0,0 +1,20 @@
+// "Replace with 'c1.newFun(this, c2)'" "true"
+
+class X {
+    @deprecated("", ReplaceWith("c1.newFun(this, c2)"))
+    fun oldFun(c1: Char, c2: Char): Char = c1.newFun(this, c2)
+
+    val c: Char = 'a'
+}
+
+fun Char.newFun(x: X, c: Char): Char = this
+
+fun foo(s: String, x: X) {
+    val chars = s.filter {
+        O.x?.<caret>oldFun(it, x.c) != 'a'
+    }
+}
+
+object O {
+    var x: X? = null
+}