NI: Prefer nullable lower bound to flexible one when substitution of type variable is performed and remember flexibility of type parameters based on flexibility of its upper bounds

^KT-32435 Fixed

compiler/testData/diagnostics/tests/functionLiterals/lambdaInLambda2.fir.kt

@@ -0,0 +1,29 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+
+// FILE: Function.java
+
+public interface Function<Param, Result> {
+    Result fun(Param param);
+}
+
+// FILE: AdapterProcessor.java
+
+public class AdapterProcessor<T, S> {
+    public AdapterProcessor(Function<? super T, ? extends S> conversion) {}
+}
+
+
+// FILE: main.kt
+
+interface PsiMethod {
+    val containingClass: PsiClass?
+}
+
+interface PsiClass
+
+fun test() {
+    // TODO: don't forget to implement preservation flexibility of java type parameters in FIR (this is the reason of error here)
+    val processor = <!INAPPLICABLE_CANDIDATE!>AdapterProcessor<!><PsiMethod, PsiClass>(
+        Function { method: PsiMethod? -> method?.containingClass }
+    )
+}

compiler/testData/diagnostics/tests/functionLiterals/lambdaInLambda2.kt

@@ -0,0 +1,29 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+
+// FILE: Function.java
+
+public interface Function<Param, Result> {
+    Result fun(Param param);
+}
+
+// FILE: AdapterProcessor.java
+
+public class AdapterProcessor<T, S> {
+    public AdapterProcessor(Function<? super T, ? extends S> conversion) {}
+}
+
+
+// FILE: main.kt
+
+interface PsiMethod {
+    val containingClass: PsiClass?
+}
+
+interface PsiClass
+
+fun test() {
+    // TODO: don't forget to implement preservation flexibility of java type parameters in FIR (this is the reason of error here)
+    val processor = AdapterProcessor<PsiMethod, PsiClass>(
+        Function { method: PsiMethod? -> method?.containingClass }
+    )
+}

compiler/testData/diagnostics/tests/functionLiterals/lambdaInLambda2.txt

@@ -0,0 +1,30 @@
+package
+
+public fun test(): kotlin.Unit
+
+public open class AdapterProcessor</*0*/ T : kotlin.Any!, /*1*/ S : kotlin.Any!> {
+    public constructor AdapterProcessor</*0*/ T : kotlin.Any!, /*1*/ S : kotlin.Any!>(/*0*/ conversion: Function<in T!, out S!>!)
+    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 interface Function</*0*/ Param : kotlin.Any!, /*1*/ Result : kotlin.Any!> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun `fun`(/*0*/ param: Param!): Result!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface PsiClass {
+    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 interface PsiMethod {
+    public abstract val containingClass: PsiClass?
+    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
+}