Reflection: add KTypeProjection and KType.arguments

#KT-8998 In Progress

compiler/testData/codegen/box/reflection/mapping/types/genericArrayElementType.kt

@@ -0,0 +1,34 @@
+// WITH_REFLECT
+// FULL_JDK
+
+import java.lang.reflect.ParameterizedType
+import kotlin.reflect.jvm.javaType
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class Bar
+fun arrayOfInvBar(): Array<Bar> = null!!
+fun arrayOfInBar(): Array<in Bar> = null!!
+fun arrayOfOutBar(): Array<out Bar> = null!!
+
+fun arrayOfInvList(): Array<List<String>> = null!!
+fun arrayOfInList(): Array<in List<String>> = null!!
+fun arrayOfOutList(): Array<out List<String>> = null!!
+
+fun box(): String {
+    // NB: in "Array<in X>", Java type of X is always Any::class.java because this is the JVM signature generated by the compiler
+
+    assertEquals(Bar::class.java, ::arrayOfInvBar.returnType.arguments.single().type!!.javaType)
+    assertEquals(Any::class.java, ::arrayOfInBar.returnType.arguments.single().type!!.javaType)
+    assertEquals(Bar::class.java, ::arrayOfOutBar.returnType.arguments.single().type!!.javaType)
+
+    val invList = ::arrayOfInvList.returnType.arguments.single().type!!.javaType
+    assertTrue(invList is ParameterizedType && invList.rawType == List::class.java, invList.toString())
+
+    assertEquals(Any::class.java, ::arrayOfInList.returnType.arguments.single().type!!.javaType)
+
+    val outList = ::arrayOfOutList.returnType.arguments.single().type!!.javaType
+    assertTrue(outList is ParameterizedType && outList.rawType == List::class.java, outList.toString())
+
+    return "OK"
+}

compiler/testData/codegen/box/reflection/mapping/types/parameterizedTypeArgument.kt

@@ -0,0 +1,22 @@
+// WITH_REFLECT
+
+import kotlin.reflect.jvm.javaType
+import kotlin.test.assertEquals
+
+fun listOfStrings(): List<String> = null!!
+
+class Foo<T>
+class Bar
+fun fooOfInvBar(): Foo<Bar> = null!!
+fun fooOfInBar(): Foo<in Bar> = null!!
+fun fooOfOutBar(): Foo<out Bar> = null!!
+
+fun box(): String {
+    assertEquals(String::class.java, ::listOfStrings.returnType.arguments.single().type!!.javaType)
+
+    assertEquals(Bar::class.java, ::fooOfInvBar.returnType.arguments.single().type!!.javaType)
+    assertEquals(Bar::class.java, ::fooOfInBar.returnType.arguments.single().type!!.javaType)
+    assertEquals(Bar::class.java, ::fooOfOutBar.returnType.arguments.single().type!!.javaType)
+
+    return "OK"
+}

compiler/testData/codegen/box/reflection/mapping/types/rawTypeArgument.kt

@@ -0,0 +1,19 @@
+// WITH_REFLECT
+// FILE: J.java
+
+import java.util.List;
+
+public interface J {
+    List foo();
+}
+
+// FILE: K.kt
+
+import kotlin.reflect.jvm.javaType
+import kotlin.test.assertEquals
+
+fun box(): String {
+    assertEquals(Any::class.java, J::foo.returnType.arguments.single().type!!.javaType)
+
+    return "OK"
+}