Restore and deprecate Function{n}/ExtensionFunction{n} classes for easier migration

Users' Java code will not break in common cases (when passing functions to
Kotlin), and deprecation warnings will be reported.

Provide an inspection with a quick fix which allows to replace deprecated
function class usages to the new classes. Include this fix to the "code
cleanup" action

compiler/testData/diagnostics/testsWithStdLib/DeprecatedFunctionClasses.kt

@@ -0,0 +1,35 @@
+// FILE: J.java
+
+import kotlin.ExtensionFunction0;
+import kotlin.ExtensionFunction1;
+import kotlin.Function0;
+import kotlin.Function1;
+import kotlin.Unit;
+
+public class J {
+    public static void f1(Function0<Unit> f) {
+        f.invoke();
+    }
+
+    public static void f2(Function1<String, String> f) {
+        f.invoke("");
+    }
+
+    public static void ef1(ExtensionFunction1<Integer, Integer, Integer> ef) {
+        ef.invoke(42, -42);
+    }
+
+    public static ExtensionFunction0<String, Unit> ef2() {
+        return null;
+    }
+}
+
+// FILE: K.kt
+
+fun foo() = J.<!JAVA_METHOD_USES_DEPRECATED_FUNCTION_CLASS!>f1 { }<!>
+
+fun bar() = J.<!JAVA_METHOD_USES_DEPRECATED_FUNCTION_CLASS!>f2 { it }<!>
+
+fun baz() = J.<!JAVA_METHOD_USES_DEPRECATED_FUNCTION_CLASS!>ef1 <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!>{<!> <!NO_THIS!>this<!> }<!>
+
+fun quux() = J.<!JAVA_METHOD_USES_DEPRECATED_FUNCTION_CLASS!>ef2()<!>

compiler/testData/diagnostics/testsWithStdLib/DeprecatedFunctionClasses.txt

@@ -0,0 +1,19 @@
+package
+
+internal fun bar(): kotlin.Unit
+internal fun baz(): kotlin.Unit
+internal fun foo(): kotlin.Unit
+internal fun quux(): kotlin.ExtensionFunction0<kotlin.String!, kotlin.Unit!>!
+
+public open class J {
+    public constructor J()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    // Static members
+    public open fun ef1(/*0*/ ef: kotlin.ExtensionFunction1<kotlin.Int!, kotlin.Int!, kotlin.Int!>!): kotlin.Unit
+    public open fun ef2(): kotlin.ExtensionFunction0<kotlin.String!, kotlin.Unit!>!
+    public open fun f1(/*0*/ f: (() -> kotlin.Unit!)!): kotlin.Unit
+    public open fun f2(/*0*/ f: ((kotlin.String!) -> kotlin.String!)!): kotlin.Unit
+}