hg: jdk/submit: 8199193: jshell tool: Add support for preview features

[robert.field at oracle.com]

Changeset: 5f63af8f9d7f
Author:    rfield
Date:      2018-04-23 09:01 -0700
URL:       http://hg.openjdk.java.net/jdk/submit/rev/5f63af8f9d7f

8199193: jshell tool: Add support for preview features
Reviewed-by: sundar

! src/jdk.jshell/share/classes/jdk/internal/jshell/tool/JShellTool.java
! src/jdk.jshell/share/classes/jdk/internal/jshell/tool/resources/l10n.properties
! src/jdk.jshell/share/classes/jdk/jshell/TaskFactory.java
+ test/langtools/jdk/jshell/ToolEnablePreviewTest.java