Add tests

compiler/testData/codegen/box/typeMapping/nullNothing.kt

@@ -0,0 +1,4 @@
+fun box(): String {
+    // kotlin.Nothing should not be loaded here
+    return (if (null is Nothing?) "O" else "FAIL1") + (if (null !is Nothing) "K" else "FAIL2")
+}

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -23595,6 +23595,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/typeMapping/nothing.kt");
         }
 
+        @TestMetadata("nullNothing.kt")
+        public void testNullNothing() throws Exception {
+            runTest("compiler/testData/codegen/box/typeMapping/nullNothing.kt");
+        }
+
         @TestMetadata("nullableNothing.kt")
         public void testNullableNothing() throws Exception {
             runTest("compiler/testData/codegen/box/typeMapping/nullableNothing.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -23595,6 +23595,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/typeMapping/nothing.kt");
         }
 
+        @TestMetadata("nullNothing.kt")
+        public void testNullNothing() throws Exception {
+            runTest("compiler/testData/codegen/box/typeMapping/nullNothing.kt");
+        }
+
         @TestMetadata("nullableNothing.kt")
         public void testNullableNothing() throws Exception {
             runTest("compiler/testData/codegen/box/typeMapping/nullableNothing.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -23600,6 +23600,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/typeMapping/nothing.kt");
         }
 
+        @TestMetadata("nullNothing.kt")
+        public void testNullNothing() throws Exception {
+            runTest("compiler/testData/codegen/box/typeMapping/nullNothing.kt");
+        }
+
         @TestMetadata("nullableNothing.kt")
         public void testNullableNothing() throws Exception {
             runTest("compiler/testData/codegen/box/typeMapping/nullableNothing.kt");