Fixed incorrect "No cast needed" warning when casting from extension function to regular one and vise versa

#KT-11780 Fixed

compiler/testData/diagnostics/tests/cast/ExtensionAsNonExtension.kt

@@ -0,0 +1,10 @@
+fun f(a: (Int) -> Unit) {
+    a as Int.() -> Unit
+
+    f1(a as Int.() -> Unit)
+}
+
+fun f1(a: Int.() -> Unit) {
+    a as (Int) -> Unit
+    f(a as (Int) -> Unit)
+}

compiler/testData/diagnostics/tests/cast/ExtensionAsNonExtension.txt

@@ -0,0 +1,4 @@
+package
+
+public fun f(/*0*/ a: (kotlin.Int) -> kotlin.Unit): kotlin.Unit
+public fun f1(/*0*/ a: kotlin.Int.() -> kotlin.Unit): kotlin.Unit