Introduce C library for Pkl (#1238)

This uses native-image to generate a C library for Pkl.
This generated library from native-image is wrapped with our own library,
in `pkl.h`.

This produces a static and a dynamic library for each os/arch variant
that Pkl currently supports.

Co-authored-by: Kushal Pisavadia <kushal.p@apple.com>
Co-authored-by: Jen Basch <jbasch94@gmail.com>
Co-authored-by: Islon Scherer <i_desouzascherer@apple.com>

pkl-server/src/test/kotlin/org/pkl/server/JvmServerTest.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,11 +19,13 @@ import java.io.PipedInputStream
 import java.io.PipedOutputStream
 import org.junit.jupiter.api.AfterEach
 import org.junit.jupiter.api.BeforeEach
+import org.pkl.commons.test.server.AbstractHttpServerTest
+import org.pkl.commons.test.server.TestTransport
 import org.pkl.core.messaging.MessageTransport
 import org.pkl.core.messaging.MessageTransports
 import org.pkl.core.util.Pair
 
-class JvmServerTest : AbstractServerTest() {
+class JvmServerTest : AbstractHttpServerTest() {
   private val transports: Pair<MessageTransport, MessageTransport> = run {
     if (USE_DIRECT_TRANSPORT) {
       MessageTransports.direct(::log)

pkl-server/src/test/kotlin/org/pkl/server/NativeServerTest.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,9 +18,11 @@ package org.pkl.server
 import org.junit.jupiter.api.AfterEach
 import org.junit.jupiter.api.BeforeEach
 import org.pkl.commons.test.Executables
+import org.pkl.commons.test.server.AbstractHttpServerTest
+import org.pkl.commons.test.server.TestTransport
 import org.pkl.core.messaging.MessageTransports
 
-class NativeServerTest : AbstractServerTest() {
+class NativeServerTest : AbstractHttpServerTest() {
   private lateinit var server: Process
   override lateinit var client: TestTransport
 

pkl-server/src/test/kotlin/org/pkl/server/TestTransport.kt

@@ -1,52 +0,0 @@
-/*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.pkl.server
-
-import java.util.concurrent.ArrayBlockingQueue
-import java.util.concurrent.BlockingQueue
-import org.assertj.core.api.Assertions.*
-import org.pkl.core.messaging.Message
-import org.pkl.core.messaging.MessageTransport
-
-class TestTransport(private val delegate: MessageTransport) : AutoCloseable {
-  val incomingMessages: BlockingQueue<Message> = ArrayBlockingQueue(10)
-
-  fun start() {
-    delegate.start({ incomingMessages.put(it) }, { incomingMessages.put(it) })
-  }
-
-  override fun close() {
-    delegate.close()
-  }
-
-  fun send(message: Message.Client.OneWay) {
-    delegate.send(message)
-  }
-
-  fun send(message: Message.Client.Request) {
-    delegate.send(message) { incomingMessages.put(it) }
-  }
-
-  fun send(message: Message.Client.Response) {
-    delegate.send(message)
-  }
-
-  inline fun <reified T : Message> receive(): T {
-    val message = incomingMessages.take()
-    assertThat(message).isInstanceOf(T::class.java)
-    return message as T
-  }
-}