title: How do I properly add --add-opens to jvmArgs in JavaExec task
body: <p>Currently I have a task that executes to run the program, something like</p>
  <pre><code>task runApp(type: JavaExec) {
      classpath = sourceSets.main.runtimeClasspath
  
      main = 'com.eonmux.somepackage'
  
      jvmArgs '-Xmx4096m'
  }
  </code></pre>
  <p>I'm trying to add --add-opens to the list of JVM args so that I can allow reflection access from my gradle packages</p>
  <p>Something like</p>
  <pre><code>task runApp(type: JavaExec) {
      classpath = sourceSets.main.runtimeClasspath
  
      main = 'com.eonmux.somepackage'
  
      jvmArgs '-Xmx4096m','--add-opens java.base/jdk.internal.loader=ALL-UNNAMED'
  }
  </code></pre>
  <p>However this gives the following error saying that the command line option is unrecognized</p>
  <pre><code>2020-12-09T16:30:56.285-0500 [INFO] [org.gradle.process.internal.DefaultExecHandle] Successfully started process 'command 'C:\Program Files\AdoptOpenJDK\jdk-11.0.6.10-openj9\bin\java.exe''
  2020-12-09T16:30:56.286-0500 [DEBUG] [org.gradle.process.internal.ExecHandleRunner] waiting until streams are handled...
  2020-12-09T16:30:56.360-0500 [ERROR] [system.err] JVMJ9VM007E Command-line option unrecognised: --add-opens java.base/jdk.internal.loader=ALL-UNNAMED
  2020-12-09T16:30:56.361-0500 [ERROR] [system.err] Error: Could not create the Java Virtual Machine.
  Could not create the Java Virtual Machine.
  
  2020-12-09T16:30:56.362-0500 [ERROR] [system.err] Error: A fatal exception has occurred. Program will exit.
  A fatal exception has occurred. Program will exit.
  
  </code></pre>
  <p>Which is strange because when I open up a command line to the Java path indicated, and run</p>
  <p>C:\Program Files\AdoptOpenJDK\jdk-11.0.6.10-openj9\bin&gt;java --add-opens</p>
  <p>I get the following message confirming its existence</p>
  <pre><code>Error: --add-opens requires modules to be specified
  </code></pre>
  <p>I'm no Gradle configuration expert, so I'd appreciate some help.</p>
  <p>This is on Windows 10x64 with the IntelliJ IDE and Gradle 6.0.1</p>