Overriding the locale for JDB

[Jakob Cornell]

Hi all,

While working on changes for JBS 8271356 I spent some time testing on locales other than en-US and found something a bit odd.  I can override the system default locale for JDB by setting the `LANG' environment variable (on Linux), and I can override the system locale for the debuggee by using `-Duser.language', but unless handling of `LANG' is implemented cross-platform in OpenJDK there doesn't seem to be a portable way of overriding the locale for JDB itself.

The reason I bring this up is that I'm adding jtreg tests for my changes, and I'm trying to have them not depend on the system default locale (even though it seems the existing tests do).  Wondering if I'm missing any better way to set the locale, in particular one that can be integrated into the `JdbTest' system.  Looks like maybe all that's missing is a way to set system properties in JDB's VM, thus enabling use of `user.language'.

Jakob