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/fir/tree/src/org/jetbrains/kotlin/fir/FirModuleCapabilities.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir
+
+import org.jetbrains.kotlin.fir.util.ConeTypeRegistry
+import org.jetbrains.kotlin.util.AttributeArrayOwner
+import org.jetbrains.kotlin.util.TypeRegistry
+import kotlin.reflect.KClass
+
+abstract class FirModuleCapability {
+    abstract val key: KClass<out FirModuleCapability>
+}
+
+class FirModuleCapabilities private constructor(
+    capabilities: List<FirModuleCapability>
+) : AttributeArrayOwner<FirModuleCapability, FirModuleCapability>() {
+
+    companion object : ConeTypeRegistry<FirModuleCapability, FirModuleCapability>() {
+
+        val Empty: FirModuleCapabilities = FirModuleCapabilities(emptyList())
+
+        fun create(attributes: List<FirModuleCapability>): FirModuleCapabilities {
+            return if (attributes.isEmpty()) {
+                Empty
+            } else {
+                FirModuleCapabilities(attributes)
+            }
+        }
+    }
+
+    init {
+        for (capability in capabilities) {
+            registerComponent(capability.key, capability)
+        }
+    }
+
+
+    override val typeRegistry: TypeRegistry<FirModuleCapability, FirModuleCapability>
+        get() = Companion
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirModuleData.kt

@@ -50,6 +50,9 @@ abstract class FirModuleData : FirSessionComponent {
     //   refactor them to make API clearer
     abstract val analyzerServices: PlatformDependentAnalyzerServices
 
+    open val capabilities: FirModuleCapabilities
+        get() = FirModuleCapabilities.Empty
+
     private var _session: FirSession? = null
     val session: FirSession
         get() = _session
@@ -73,7 +76,8 @@ class FirModuleDataImpl(
     override val dependsOnDependencies: List<FirModuleData>,
     override val friendDependencies: List<FirModuleData>,
     override val platform: TargetPlatform,
-    override val analyzerServices: PlatformDependentAnalyzerServices
+    override val analyzerServices: PlatformDependentAnalyzerServices,
+    override val capabilities: FirModuleCapabilities = FirModuleCapabilities.Empty
 ) : FirModuleData()
 
 val FirSession.nullableModuleData: FirModuleData? by FirSession.nullableSessionComponentAccessor()

compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirTypeUtils.kt

@@ -31,6 +31,9 @@ val FirTypeRef.coneType: ConeKotlinType
     get() = coneTypeSafe()
         ?: error("Expected FirResolvedTypeRef with ConeKotlinType but was ${this::class.simpleName} ${render()}")
 
+val FirTypeRef.coneTypeOrNull: ConeKotlinType?
+    get() = coneTypeSafe()
+
 val FirTypeRef.isAny: Boolean get() = isBuiltinType(StandardClassIds.Any, false)
 val FirTypeRef.isNullableAny: Boolean get() = isBuiltinType(StandardClassIds.Any, true)
 val FirTypeRef.isNothing: Boolean get() = isBuiltinType(StandardClassIds.Nothing, false)