RFR: 8183021: Fix failing jshell tests on Windows

[Jan Lahoda]

Hi,

Two JShell tests are failing on Win:
-jdk/jshell/ToolBasicTest.java, seems that 
System.getProperty("user.home") may return forward slashes, but the 
tests expects the canonical backward slash. The proposed solution is to 
normalize the path using Paths.get(...).
-jdk/jshell/ToolMultilineSnippetHistoryTest.java, seems JShellTool 
prints \n, while the test expects \r\n. The proposed solution is to 
change the relevant place in JShellTool to use println to improve 
testability.

Bug:
https://bugs.openjdk.java.net/browse/JDK-8183021

Webrev:
http://cr.openjdk.java.net/~jlahoda/8183021/webrev.00/

Thanks,
     Jan