Intentions: function <-> property conversion

idea/testData/intentions/convertFunctionToProperty/invoke.kt

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+// IS_APPLICABLE: false
+class A(val n: Int) {
+    fun <caret>invoke(): Int = 1
+}
+
+fun test(a: A) {
+    val n = a()
+}