Analyze Data Flow: Support callable references

#KT-11994 In Progress

idea/testData/slicer/outflow/funResultViaCallableRefWithAssignment.kt

@@ -0,0 +1,11 @@
+// FLOW: OUT
+
+fun foo(f: (Int) -> Int): Int {
+    return f(1)
+}
+
+fun test() {
+    fun bar(n: Int) = <caret>n
+    val f = ::bar
+    val x = foo(f)
+}