K2: support implicit integer to unsigned conversions...

with dedicated opt-in language feature and special
annotation or module capability.
Not intended for a general use, solves specific K/N
scenario with interop libs.
#KT-55902 fixed

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

@@ -39805,6 +39805,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)
     public static class UnsignedTypes extends AbstractLightAnalysisModeTest {
+        @TestMetadata("signedToUnsignedConversions.kt")
+        public void ignoreSignedToUnsignedConversions() throws Exception {
+            runTest("compiler/testData/codegen/box/unsignedTypes/signedToUnsignedConversions.kt");
+        }
+
         private void runTest(String testDataFilePath) throws Exception {
             KotlinTestUtils.runTest(this::doTest, TargetBackend.JVM, testDataFilePath);
         }