jdk incubator module cannot be resolved

Trying to use OpenJDK project Panama's new incubator module for native memory/function access, VSCode shows "The import jdk.incubator cannot be resolved".

Environment

• Operating System: MacOS
• JDK version: Local build of Project Panama (https://openjdk.java.net/projects/panama/)
• Visual Studio Code version: 1.40.1
• Java extension version: 0.53.1

Steps To Reproduce

In general, create a project use jdk incubator module should see this

Be more specific to this,

1. Obtain a build for project panama foreign-abi branch
2. Set up maven toolchain

<toolchains>
	<!-- JDK toolchains -->
	<toolchain>
		<type>jdk</type>
		<provides>
			<version>14</version>
			<vendor>panama.mem</vendor>
		</provides>
		<configuration>
			<jdkHome>path to the build here</jdkHome>
		</configuration>
	</toolchain>
</toolchains>

3. Open attached sample project
   attach a sample project sample.zip

Current Result

maven build works fine, but VSCode shows "The import jdk.incubator cannot be resolved" on import lines and code using API from the module are shown as cannot be resolved.

Expected Result

Package and APIs are resolved

Additional Informations

It would be helpful be able to tweak javac options like --add-modules, --add-exports in workspace setting for simple projects like testing.

Set java.home just is not enough.

In order for this project to build with VSCode, I am forced to create maven project so that I can add this compiler options.

Begin with the attached sample.zip and its Maven toolchain setup; reproduce the unresolved jdk.incubator imports in VSCode using the listed Project Panama JDK. Compare the Maven build's module handling with the extension's workspace behavior, then verify that the package and APIs resolve and that --add-modules/--add-exports can be supplied for simple projects.