K2: expand types during smartcasting to prevent redundant intersections

#KT-53184 Fixed

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -17829,6 +17829,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/fir/flexibleIntegerLiterals.kt");
         }
 
+        @Test
+        @TestMetadata("getOnNullableTypeAlias.kt")
+        public void testGetOnNullableTypeAlias() throws Exception {
+            runTest("compiler/testData/codegen/box/fir/getOnNullableTypeAlias.kt");
+        }
+
         @Test
         @TestMetadata("implicitNothingInDelegate.kt")
         public void testImplicitNothingInDelegate() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/ir/Fir2IrTextTestGenerated.java

@@ -2632,6 +2632,12 @@ public class Fir2IrTextTestGenerated extends AbstractFir2IrTextTest {
             runTest("compiler/testData/ir/irText/firProblems/recursiveCapturedTypeInPropertyReference.kt");
         }
 
+        @Test
+        @TestMetadata("reflectGetOnNullableTypeAlias.kt")
+        public void testReflectGetOnNullableTypeAlias() throws Exception {
+            runTest("compiler/testData/ir/irText/firProblems/reflectGetOnNullableTypeAlias.kt");
+        }
+
         @Test
         @TestMetadata("SafeLetWithReturn.kt")
         public void testSafeLetWithReturn() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/ir/LightTreeFir2IrTextTestGenerated.java

@@ -2632,6 +2632,12 @@ public class LightTreeFir2IrTextTestGenerated extends AbstractLightTreeFir2IrTex
             runTest("compiler/testData/ir/irText/firProblems/recursiveCapturedTypeInPropertyReference.kt");
         }
 
+        @Test
+        @TestMetadata("reflectGetOnNullableTypeAlias.kt")
+        public void testReflectGetOnNullableTypeAlias() throws Exception {
+            runTest("compiler/testData/ir/irText/firProblems/reflectGetOnNullableTypeAlias.kt");
+        }
+
         @Test
         @TestMetadata("SafeLetWithReturn.kt")
         public void testSafeLetWithReturn() throws Exception {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/ResolveUtils.kt

@@ -361,10 +361,10 @@ private inline fun <T : FirExpression> BodyResolveComponents.transformExpression
             SmartcastStability.STABLE_VALUE
         }
 
-    val originalType = expression.resultType.coneType
+    val originalType = expression.resultType.coneType.fullyExpandedType(session)
     val allTypes = typesFromSmartCast.also {
         if (originalType !is ConeStubType) {
-            it += originalType
+            it += originalType.fullyExpandedType(session)
         }
     }
     if (allTypes.all { it is ConeDynamicType }) return null