[FIR] Properly handle that type variable is contained in inv or contravar positions

#KT-45344 Fixed

compiler/testData/diagnostics/tests/inference/constraints/definitelyNotNullTypeInReturnPosition.fir.kt

@@ -140,8 +140,8 @@ class Main<L>(x: L?, y: L) {
     val x120 = foo12(x!!)
     val x121 = foo12(y!!)
 
-    val x122 = foo12(x)
-    val x123 = foo12(y)
+    val x122 = <!INAPPLICABLE_CANDIDATE!>foo12<!>(x)
+    val x123 = <!INAPPLICABLE_CANDIDATE!>foo12<!>(y)
 
     val x133 = Foo13(x).foo1(y)
     val x135 = Foo13(y).foo1(y)

compiler/testData/diagnostics/tests/inference/constraints/definitelyNotNullTypeInvariantPosition.fir.kt

@@ -1,24 +0,0 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_EXPRESSION -UNUSED_VARIABLE
-
-class Inv<T>(val x: T?)
-
-fun <K> create(y: K) = Inv(y)
-fun <K> createPrivate(y: K) = Inv(y)
-
-fun takeInvInt(i: Inv<Int>) {}
-
-fun <S> test(i: Int, s: S) {
-    val a = Inv(s)
-
-    a
-
-    val b = create(i)
-
-    b
-
-    val c = createPrivate(i)
-
-    c
-
-    <!INAPPLICABLE_CANDIDATE!>takeInvInt<!>(create(i))
-}

compiler/testData/diagnostics/tests/inference/constraints/definitelyNotNullTypeInvariantPosition.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_EXPRESSION -UNUSED_VARIABLE
 
 class Inv<T>(val x: T?)

compiler/testData/diagnostics/tests/inference/constraints/wrongApproximationWithDefNotNullTypesAndDelegates.kt

@@ -13,4 +13,4 @@ class Foo {
 
         operator fun setValue(thisRef: Foo, property: KProperty<*>, value: T) {}
     }
-}
+}