[8u40] Request for approval: JDK-8057691: Nashorn: let & const declarations are not shared between scripts

[Hannes Wallnoefer]

JDK-8057691: Nashorn: let & const declarations are not shared between 
scripts

Please approve backport of JDK-8057691 to 8u40.

Bug: https://bugs.openjdk.java.net/browse/JDK-8057691
Webrev: http://cr.openjdk.java.net/~hannesw/8057691/
Review thread: 
http://mail.openjdk.java.net/pipermail/nashorn-dev/2014-November/003877.html
Changeset: http://hg.openjdk.java.net/jdk9/dev/nashorn/rev/a723569d0559

The patch applies cleanly to 8u40 after fixing path names except for the 
change in jdk/nashorn/internal/parser/Parser.java.
However, that change is quite easy to reconstruct as I just undid a 
change introduced in JDK-8051889.

Change to Parser.java in JDK9: 
http://hg.openjdk.java.net/jdk9/dev/nashorn/rev/a723569d0559#l4.7
Change that needs to be undone in JDK8: 
http://hg.openjdk.java.net/jdk8u/jdk8u-dev/nashorn/rev/b7a2db4de254#l13.26
Change backported to JDK8u-dev: 
http://cr.openjdk.java.net/~hannesw/8057691/webrev-8u-dev/src/jdk/nashorn/internal/parser/Parser.java.udiff.html

Thanks,
Hannes