SLC: account for upperbounds when computing nullability of type parameter

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/symbolLightUtils.kt

@@ -149,13 +149,9 @@ internal fun KtAnalysisSession.getTypeNullability(ktType: KtType): NullabilityTy
     if (ktType.isUnit) return NullabilityType.NotNull
 
     if (ktType is KtTypeParameterType) {
-//        TODO Make supertype checking
-//        val subtypeOfNullableSuperType = context.firRef.withFir(phase) {
-//            it.session.typeCheckerContext.nullableAnyType().isSupertypeOf(it.session.typeCheckerContext, coneType)
-//        }
-//        if (!subtypeOfNullableSuperType) return NullabilityType.NotNull
-
-        return if (!ktType.isMarkedNullable) NullabilityType.Unknown else NullabilityType.NotNull
+        if (ktType.isMarkedNullable) return NullabilityType.Nullable
+        val subtypeOfNullableSuperType = ktType.symbol.upperBounds.all { upperBound -> upperBound.canBeNull }
+        return if (!subtypeOfNullableSuperType) NullabilityType.NotNull else NullabilityType.Unknown
     }
     if (ktType !is KtClassType) return NullabilityType.NotNull
 

compiler/testData/asJava/lightClasses/nullabilityAnnotations/Generic.fir.java

@@ -1,12 +0,0 @@
-public abstract interface Generic /* Generic*/<N, NN>  {
-  @org.jetbrains.annotations.Nullable()
-  public abstract N a1(@org.jetbrains.annotations.Nullable() N);//  a1(N)
-
-  @org.jetbrains.annotations.Nullable()
-  public abstract NN b1(@org.jetbrains.annotations.Nullable() NN);//  b1(NN)
-
-  public abstract N a(N);//  a(N)
-
-  public abstract NN b(NN);//  b(NN)
-
-}