[NI] Make behaviour of anonymous functions consistent with lambdas

Fix completion of anonymous functions with expression body without expected type.
Premature completion led to losing type info from outer calls.
Also report type mismatches on empty lambda expressions.

KT-34729 In progress

compiler/testData/diagnostics/tests/functionAsExpression/InferenceParametersTypes.kt

@@ -12,7 +12,7 @@ fun test(a: (Int) -> Int) {
 }
 
 fun test2(a: () -> List<Int>) {
-    test2(fun () = <!NI;NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER, OI;TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>listOf<!>())
+    test2(fun () = <!OI;TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>listOf<!>())
 }
 
 val a: (Int) -> Unit = fun(x) { checkSubtype<Int>(x) }

compiler/testData/diagnostics/tests/generics/kt34729.fir.kt

@@ -0,0 +1,19 @@
+// !WITH_NEW_INFERENCE
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !LANGUAGE: +NewInference
+
+interface ILength {
+    val length: Int
+}
+
+class Impl(override val length: Int) : ILength
+
+fun <T> foo(a: (Int) -> T) = 0
+fun <T : ILength> bar(a: (Int) -> T) {
+    a(42).length
+}
+
+fun test() {
+    foo<String> { }
+    bar<Impl> { }
+}

compiler/testData/diagnostics/tests/generics/kt34729.kt

@@ -0,0 +1,19 @@
+// !WITH_NEW_INFERENCE
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !LANGUAGE: +NewInference
+
+interface ILength {
+    val length: Int
+}
+
+class Impl(override val length: Int) : ILength
+
+fun <T> foo(a: (Int) -> T) = 0
+fun <T : ILength> bar(a: (Int) -> T) {
+    a(42).length
+}
+
+fun test() {
+    foo<String> <!NI;TYPE_MISMATCH!>{ <!OI;TYPE_MISMATCH!><!>}<!>
+    bar<Impl> <!NI;TYPE_MISMATCH, NI;TYPE_MISMATCH!>{ <!OI;TYPE_MISMATCH!><!>}<!>
+}

compiler/testData/diagnostics/tests/generics/kt34729.txt

@@ -0,0 +1,20 @@
+package
+
+public fun </*0*/ T : ILength> bar(/*0*/ a: (kotlin.Int) -> T): kotlin.Unit
+public fun </*0*/ T> foo(/*0*/ a: (kotlin.Int) -> T): kotlin.Int
+public fun test(): kotlin.Unit
+
+public interface ILength {
+    public abstract val length: kotlin.Int
+    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
+}
+
+public final class Impl : ILength {
+    public constructor Impl(/*0*/ length: kotlin.Int)
+    public open override /*1*/ val length: kotlin.Int
+    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
+}

compiler/testData/diagnostics/tests/inference/completion/anonymousFunction.fir.kt

@@ -0,0 +1,22 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+fun take(fn: () -> List<String>) {}
+fun <L> inferFromLambda(fn: () -> L): L = TODO()
+
+fun <T> materialize(): T = TODO()
+fun <I> id(arg: I) = arg
+
+fun testFunctions() {
+    take { materialize() }
+    take(fun() = materialize())
+    take(fun(): List<String> = materialize())
+    take(fun(): List<String> {
+        return materialize()
+    })
+}
+
+fun testNestedCalls() {
+    id<String>(inferFromLambda { materialize() })
+    id<String>(inferFromLambda(fun() = materialize()))
+}

compiler/testData/diagnostics/tests/inference/completion/anonymousFunction.kt

@@ -0,0 +1,22 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+fun take(fn: () -> List<String>) {}
+fun <L> inferFromLambda(fn: () -> L): L = TODO()
+
+fun <T> materialize(): T = TODO()
+fun <I> id(arg: I) = arg
+
+fun testFunctions() {
+    take { materialize() }
+    take(fun() = materialize())
+    take(fun(): List<String> = materialize())
+    take(fun(): List<String> {
+        return materialize()
+    })
+}
+
+fun testNestedCalls() {
+    id<String>(inferFromLambda { materialize() })
+    id<String>(inferFromLambda(fun() = materialize()))
+}

compiler/testData/diagnostics/tests/inference/completion/anonymousFunction.txt

@@ -0,0 +1,8 @@
+package
+
+public fun </*0*/ I> id(/*0*/ arg: I): I
+public fun </*0*/ L> inferFromLambda(/*0*/ fn: () -> L): L
+public fun </*0*/ T> materialize(): T
+public fun take(/*0*/ fn: () -> kotlin.collections.List<kotlin.String>): kotlin.Unit
+public fun testFunctions(): kotlin.Unit
+public fun testNestedCalls(): kotlin.Unit