[FIR] Fix ambiguity of Throws and other std annotations importing

Including `SharedImmutable` and `ThreadLocal`

Simplify code, remove `DefaultImportPriority.KOTLIN_THROWS`

Introduce `FirNativeClassMapper`

compiler/fir/native/src/org/jetbrains/kotlin/fir/backend/native/FirNativeClassMapper.kt

@@ -0,0 +1,32 @@
+/*
+ * 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.backend.native
+
+import org.jetbrains.kotlin.fir.declarations.FirClassLikeDeclaration
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.scopes.FirPlatformClassMapper
+import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.name.NativeRuntimeNames
+
+class FirNativeClassMapper : FirPlatformClassMapper() {
+    override fun getCorrespondingPlatformClass(declaration: FirClassLikeDeclaration): FirRegularClass? {
+        return null
+    }
+
+    override fun getCorrespondingPlatformClass(classId: ClassId?): ClassId? {
+        return null
+    }
+
+    override fun getCorrespondingKotlinClass(classId: ClassId?): ClassId? {
+        return null
+    }
+
+    override val classTypealiasesThatDontCauseAmbiguity: Map<ClassId, ClassId> = mapOf(
+        NativeRuntimeNames.Annotations.Throws to NativeRuntimeNames.Annotations.ThrowsAlias,
+        NativeRuntimeNames.Annotations.SharedImmutable to NativeRuntimeNames.Annotations.SharedImmutableAlias,
+        NativeRuntimeNames.Annotations.ThreadLocal to NativeRuntimeNames.Annotations.ThreadLocalAlias
+    )
+}