Support KParameter.kind: instance, extension receiver, or value

compiler/testData/codegen/boxWithStdlib/reflection/parameters/kinds.kt

@@ -0,0 +1,18 @@
+import kotlin.reflect.*
+import kotlin.reflect.KParameter.Kind.*
+import kotlin.test.assertEquals
+
+class A {
+    fun Int.foo(x: String) {}
+
+    inner class Inner(s: String) {}
+}
+
+fun box(): String {
+    val foo = A::class.memberExtensionFunctions.single()
+
+    assertEquals(listOf(INSTANCE, EXTENSION_RECEIVER, VALUE), foo.parameters.map { it.kind })
+    assertEquals(listOf(INSTANCE, VALUE), A::Inner.parameters.map { it.kind })
+
+    return "OK"
+}

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java

@@ -3597,6 +3597,12 @@ public class BlackBoxWithStdlibCodegenTestGenerated extends AbstractBlackBoxCode
                 doTestWithStdlib(fileName);
             }
 
+            @TestMetadata("kinds.kt")
+            public void testKinds() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/reflection/parameters/kinds.kt");
+                doTestWithStdlib(fileName);
+            }
+
             @TestMetadata("propertySetter.kt")
             public void testPropertySetter() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/reflection/parameters/propertySetter.kt");

core/builtins/src/kotlin/reflect/KParameter.kt

@@ -40,4 +40,24 @@ public interface KParameter : KAnnotatedElement {
      * not the individual element.
      */
     public val type: KType
+
+    /**
+     * Kind of this parameter.
+     */
+    public val kind: Kind
+
+    /**
+     * Kind represents a particular position of the parameter declaration in the source code,
+     * such as an instance, an extension receiver parameter or a value parameter.
+     */
+    public enum class Kind {
+        /** Instance required to make a call to the member, or an outer class instance for an inner class constructor. */
+        INSTANCE,
+
+        /** Extension receiver of an extension function or property. */
+        EXTENSION_RECEIVER,
+
+        /** Ordinary named value parameter. */
+        VALUE,
+    }
 }

core/reflection.jvm/src/kotlin/reflect/jvm/internal/KCallableImpl.kt

@@ -36,15 +36,15 @@ interface KCallableImpl<out R> : KCallable<R>, KAnnotatedElementImpl {
             var index = 0
 
             if (descriptor.dispatchReceiverParameter != null) {
-                result.add(KParameterImpl(this, index++) { descriptor.dispatchReceiverParameter!! })
+                result.add(KParameterImpl(this, index++, KParameter.Kind.INSTANCE) { descriptor.dispatchReceiverParameter!! })
             }
 
             if (descriptor.extensionReceiverParameter != null) {
-                result.add(KParameterImpl(this, index++) { descriptor.extensionReceiverParameter!! })
+                result.add(KParameterImpl(this, index++, KParameter.Kind.EXTENSION_RECEIVER) { descriptor.extensionReceiverParameter!! })
             }
 
             for (i in descriptor.valueParameters.indices) {
-                result.add(KParameterImpl(this, index++) { descriptor.valueParameters[i] })
+                result.add(KParameterImpl(this, index++, KParameter.Kind.VALUE) { descriptor.valueParameters[i] })
             }
 
             result.trimToSize()

core/reflection.jvm/src/kotlin/reflect/jvm/internal/KParameterImpl.kt

@@ -25,6 +25,7 @@ import kotlin.reflect.KType
 class KParameterImpl(
         val callable: KCallableImpl<*>,
         override val index: Int,
+        override val kind: KParameter.Kind,
         computeDescriptor: () -> ParameterDescriptor
 ) : KParameter, KAnnotatedElementImpl {
     private val descriptor: ParameterDescriptor by ReflectProperties.lazySoft(computeDescriptor)