[NI] Dont' add trivial constraints with Nothing from incorporation

#KT-24490 Fixed
 #KT-26816 Fixed

compiler/testData/diagnostics/tests/inference/nothingType/generateConstraintWithInnerNothingType.kt

@@ -0,0 +1,13 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+class Out<out T>(val o: T)
+
+interface Base
+class Inv<K> : Base
+
+fun <S> select(x: S, y: S): S = x
+
+fun test(a1: Inv<Number>, a2: Inv<Nothing?>): Out<Base> {
+    return select(Out(a1), Out(a2))
+}

compiler/testData/diagnostics/tests/inference/nothingType/generateConstraintWithInnerNothingType.txt

@@ -0,0 +1,25 @@
+package
+
+public fun </*0*/ S> select(/*0*/ x: S, /*1*/ y: S): S
+public fun test(/*0*/ a1: Inv<kotlin.Number>, /*1*/ a2: Inv<kotlin.Nothing?>): Out<Base>
+
+public interface Base {
+    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 Inv</*0*/ K> : Base {
+    public constructor Inv</*0*/ K>()
+    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 Out</*0*/ out T> {
+    public constructor Out</*0*/ out T>(/*0*/ o: T)
+    public final val o: T
+    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/nothingType/implicitNothingConstraintFromReturn.kt

@@ -0,0 +1,15 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+class Simple
+
+fun test(s: Simple?): Simple? {
+    myRun {
+        s?.let { return it }
+    }
+
+    return s
+}
+
+inline fun <R> myRun(block: () -> R): R = TODO()
+inline fun <K, V> K.let(block: (K) -> V): V = TODO()

compiler/testData/diagnostics/tests/inference/nothingType/implicitNothingConstraintFromReturn.txt

@@ -0,0 +1,12 @@
+package
+
+public inline fun </*0*/ R> myRun(/*0*/ block: () -> R): R
+public fun test(/*0*/ s: Simple?): Simple?
+public inline fun </*0*/ K, /*1*/ V> K.let(/*0*/ block: (K) -> V): V
+
+public final class Simple {
+    public constructor Simple()
+    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/nothingType/kt24490.kt

@@ -0,0 +1,13 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+
+fun <T> bar(i: T): T = i
+fun foo(i: Int) = i
+
+fun dontRun(body: () -> Unit) = Unit
+
+class Case1 {
+    fun test() {
+        dontRun { val x = bar(bar { -> bar { -> 2} }) }
+    }
+}

compiler/testData/diagnostics/tests/inference/nothingType/kt24490.txt

@@ -0,0 +1,13 @@
+package
+
+public fun </*0*/ T> bar(/*0*/ i: T): T
+public fun dontRun(/*0*/ body: () -> kotlin.Unit): kotlin.Unit
+public fun foo(/*0*/ i: kotlin.Int): kotlin.Int
+
+public final class Case1 {
+    public constructor Case1()
+    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 final fun test(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/inference/nothingType/nestedLambdaInferenceWithIncorporationOfVariables.kt

@@ -0,0 +1,12 @@
+// !LANGUAGE: +NewInference
+
+fun <K> id1(k: K): K = k
+fun <V> id2(v: V): V = v
+
+fun test() {
+    id1 {
+        id2 {
+            3
+        }
+    }
+}

compiler/testData/diagnostics/tests/inference/nothingType/nestedLambdaInferenceWithIncorporationOfVariables.txt

@@ -0,0 +1,5 @@
+package
+
+public fun </*0*/ K> id1(/*0*/ k: K): K
+public fun </*0*/ V> id2(/*0*/ v: V): V
+public fun test(): kotlin.Unit