hg: jdk/jdk: 8210808: jshell tool: only considers the first snippet of the external editor

[robert.field at oracle.com]

Changeset: f300b4ca2637
Author:    rfield
Date:      2018-10-29 08:34 -0700
URL:       http://hg.openjdk.java.net/jdk/jdk/rev/f300b4ca2637

8210808: jshell tool: only considers the first snippet of the external editor
Reviewed-by: jlahoda, sundar

! src/jdk.jshell/share/classes/jdk/internal/jshell/tool/JShellTool.java
! test/langtools/jdk/jshell/EditorTestBase.java
! test/langtools/jdk/jshell/ExternalEditorTest.java