Publish executables for pkldoc, pkl-codegen-java, pkl-codegen-kotlin (#1023)

This adds logic to build and publish the other executables related to Pkl.

These are:

* pkl-doc
* pkl-codegen-kotlin
* pkl-codegen-java

pkl-codegen-kotlin and pkl-codegen-java are published as executable JARs, whereas pkldoc is published both as an executable JAR, and also native executables (matching the set of os/arch supported by Pkl).

The reason this only publishes executable JARs for pkl-codegen-kotlin and pkl-codegen-java is because we expect that the Java requirement is not a problem for these users, and that the native executable provides negligible added value.

As part of this, the following changes are made:

* Introduce `pklJavaExecutable` plugin, which sets up building and publishing of executable JAR.
* Introduce `pklNativeExecutable` plugin, which sets up building and publishing of native executables.
* Introduce `NativeImageBuild` Gradle task, which knows how to build native-image executables.
* Introduce `ExecutableSpec` extension, for projects that publish executables to configure how those executables should be published.
* `./griddles buildNative`, by default, will only build the executable of the host OS/Arch, and will no longer cross-build.
* The target arch of `./gradlew buildNative` can be changed using `-Dpkl.targetArch=<aarch64|amd64>`.
* On linux/amd64 only, with `./gradlew buildNative`, a statically linked executable can be built using `-Dpkl.musl=true`
* Make `javaExecutable` a dependency of `assemble`
* Make `testStartJavaExecutable` a dependency of `check`
* Change name `pklNativeBuild` to `pklNativeLifecycle` to better match the plugin's purpose
* Remove Truffle SVM classes from main source set (don't publish these classes as part of the pkl-cli JAR)
* Change CircleCI definition to publish new executables
* Change CircleCI definition to call `buildNative` instead of individual task names

.circleci/jobs/BuildNativeJob.pkl

@@ -24,8 +24,20 @@ arch: "amd64"|"aarch64"
 /// Whether to link to musl. Otherwise, links to glibc.
 musl: Boolean = false
 
+/// The Gradle project under which to generate the executable
+project: String
+
 javaVersion = "21.0"
 
+extraGradleArgs {
+  when (os == "macOS" && arch == "amd64") {
+    "-Dpkl.targetArch=\(arch)"
+  }
+  when (musl) {
+    "-Dpkl.musl=true"
+  }
+}
+
 local setupLinuxEnvironment: Config.RunStep =
   let (muslVersion = "1.2.2")
   let (zlibVersion = "1.2.13")
@@ -131,24 +143,18 @@ steps {
   }
   new Config.RunStep {
     name = "gradle buildNative"
-    local _os =
-      if (module.os == "macOS") "mac"
-      else if (musl) "alpine"
-      else if (module.os == "windows") "windows"
-      else "linux"
-    local jobName = "\(_os)Executable\(arch.capitalize())"
     when (module.os == "windows") {
       shell = "bash.exe"
     }
     command = #"""
       export PATH=~/staticdeps/bin:$PATH
-      ./gradlew \#(module.gradleArgs) pkl-cli:\#(jobName) pkl-core:test\#(jobName.capitalize()) pkl-server:test\#(jobName.capitalize())
+      ./gradlew \#(module.gradleArgs) \#(project):buildNative
       """#
   }
   new Config.PersistToWorkspaceStep {
     root = "."
     paths {
-      "pkl-cli/build/executable/"
+      "\(project)/build/executable/"
     }
   }
 }

.circleci/jobs/DeployJob.pkl

@@ -30,11 +30,14 @@ steps {
   new Config.RunStep {
     command = "./gradlew \(self.gradleArgs) \(module.command)"
   }
-  // add jpkl to workspace so it gets published as a GitHub release
+  // add Java executables to workspace so they get published as a GitHub release
   new Config.PersistToWorkspaceStep {
     root = "."
     paths {
       "pkl-cli/build/executable/"
+      "pkl-doc/build/executable/"
+      "pkl-codegen-java/build/executable/"
+      "pkl-codegen-kotlin/build/executable/"
     }
   }
 }

.circleci/jobs/GradleJob.pkl

@@ -51,8 +51,11 @@ fixed gradleArgs = new Listing {
   when (isRelease) {
     "-DreleaseBuild=true"
   }
+  ...extraGradleArgs
 }.join(" ")
 
+extraGradleArgs: Listing<String>
+
 steps: Listing<Config.Step>
 
 job: Config.Job = new {