[Swift Export] initial infrastructure for Swift IR

New modules 'sir', 'sir-passes', and 'sir-analysis-api' were added under
'native:swift' for creating and manipulating Swift IR elements.

* `sir` contains the implementation of Swift IR.
* `sir-analysis-api` contains translation from Analysis API to SIR.
* `sir-passses` contains transformation passes.

This groundwork will allow to progress with the Swift IR.

native/swift/sir/build.gradle.kts

@@ -0,0 +1,17 @@
+plugins {
+    kotlin("jvm")
+}
+
+description = "Swift Intermediate Representation"
+
+dependencies {
+    compileOnly(kotlinStdlib())
+
+    testImplementation(libs.junit4)
+    testImplementation(projectTests(":compiler:tests-common"))
+}
+
+sourceSets {
+    "main" { projectDefault() }
+    "test" { projectDefault() }
+}

native/swift/sir/src/org/jetbrains/kotlin/sir/SirElement.kt

@@ -0,0 +1,12 @@
+/*
+ * 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.sir
+
+/**
+ * A marker interface that denotes Swift IR elements.
+ */
+interface SirElement {
+}

native/swift/sir/tests/org/jetbrains/kotlin/sir/SirTest.kt

@@ -0,0 +1,23 @@
+/*
+ * 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.sir
+
+import org.junit.Test
+import kotlin.test.assertTrue
+
+class SirTest {
+
+    // TODO: Just a fake test to validate that everything is working. Feel free to delete.
+    @Test
+    fun exampleTest() {
+        val fakeElement = produceSwiftElement()
+        assertTrue(fakeElement is SirElement)
+    }
+
+    private fun produceSwiftElement(): Any {
+        return object : SirElement {}
+    }
+}