KT-8716 Exception on attempt to implement function

#KT-8716 Fixed

idea/testData/codeInsight/overrideImplement/ImplementFunctionType.kt

@@ -0,0 +1,3 @@
+class C : (String) -> Boolean {
+    <caret>
+}

idea/testData/codeInsight/overrideImplement/implementFunctionType.kt.after

@@ -0,0 +1,5 @@
+class C : (String) -> Boolean {
+    override fun invoke(p1: String): Boolean {
+        <selection><caret>throw UnsupportedOperationException()</selection>
+    }
+}