RFR 8166183: jshell tool: on return from Ctrl-Z, garbage on screen, dies with Ctrl-C

[Jan Lahoda]

Hello,

When jshell or jjs are suspended and resumed, the terminal is reset to 
un-raw/cooked mode and jline editing is not working properly (as that 
requires raw mode). The solution I know about is to reset the terminal 
to raw mode on resume. This can be achieved using 
jdk.internal.misc.Signal (or sun.misc.Signal), which seems mostly fine 
to me for jshell and jjs, as s.m.Signal is a critical internal API per 
JEP 260. (Use of Signal would seem less fine to me in jdk.internal.le, 
as Signal is still an internal API.)

Bug:
https://bugs.openjdk.java.net/browse/JDK-8166183

Webrevs:
jdk repository:
http://cr.openjdk.java.net/~jlahoda/8166183/jdk.00/

langtools repository:
http://cr.openjdk.java.net/~jlahoda/8166183/langtools.00/

nashorn repository:
http://cr.openjdk.java.net/~jlahoda/8166183/nashorn.00/

Any feedback is welcome.

Thanks,
      Jan