NI: discard def not null types if they appear in return positions, in inv or in variance

^KT-37343 Fixed

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/types/ConeInferenceContext.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
 import org.jetbrains.kotlin.fir.types.impl.ConeTypeParameterTypeImpl
 import org.jetbrains.kotlin.types.AbstractTypeChecker
 import org.jetbrains.kotlin.types.AbstractTypeCheckerContext
+import org.jetbrains.kotlin.types.checker.NewCapturedType
 import org.jetbrains.kotlin.types.model.*
 import org.jetbrains.kotlin.utils.addToStdlib.cast
 
@@ -267,6 +268,16 @@ interface ConeInferenceContext : TypeSystemInferenceExtensionContext, ConeTypeCo
         return this.constructor.typeParameterMarker
     }
 
+    override fun CapturedTypeMarker.withNotNullProjection(): KotlinTypeMarker {
+        require(this is ConeCapturedType)
+        return this // TODO
+    }
+
+    override fun CapturedTypeMarker.isProjectionNotNull(): Boolean {
+        require(this is ConeCapturedType)
+        return false // TODO
+    }
+
     override fun DefinitelyNotNullTypeMarker.original(): SimpleTypeMarker {
         require(this is ConeDefinitelyNotNullType)
         return this.original as SimpleTypeMarker

compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirOldFrontendDiagnosticsTestGenerated.java

@@ -10725,6 +10725,16 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
                 runTest("compiler/testData/diagnostics/tests/inference/constraints/constraintOnFunctionLiteral.kt");
             }
 
+            @TestMetadata("definitelyNotNullTypeInArguments.kt")
+            public void testDefinitelyNotNullTypeInArguments() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inference/constraints/definitelyNotNullTypeInArguments.kt");
+            }
+
+            @TestMetadata("definitelyNotNullTypeInReturnPosition.kt")
+            public void testDefinitelyNotNullTypeInReturnPosition() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inference/constraints/definitelyNotNullTypeInReturnPosition.kt");
+            }
+
             @TestMetadata("definitelyNotNullTypeInvariantPosition.kt")
             public void testDefinitelyNotNullTypeInvariantPosition() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/inference/constraints/definitelyNotNullTypeInvariantPosition.kt");