RFR: 8149591 - Prepare hotspot for GTest

[Kim Barrett]

> On Apr 29, 2016, at 9:47 PM, Igor Ignatyev <igor.ignatyev at oracle.com> wrote:
> 
> Hi,
> 
> I’d like to renew this RFR.
> 
> besides updated previous changes, new webrev contains two new things:
> - new vm-flag — ExecutingUnitTests, we use it in debug jvm to print a clean error message (w/o assert, line, file, etc). it is needed to simplify comparing error message in “death” tests (the tests which intentionally cause crashes/asserts)
> - if CreateCoredumpOnCrash is false, we don't determine default core path
> 
> webrev: http://cr.openjdk.java.net/~iignatyev/8149591/webrev.00/
> JBS: https://bugs.openjdk.java.net/browse/JDK-8149591
> 
> Thanks,
> — Igor

In addition to the FormatBufferDummy question in earlier email, here
are my comments:

------------------------------------------------------------------------------
src/share/vm/services/management.cpp
1612   FormatBuffer<80> error_msg("%s", "");
[renamed variable err_msg => error_msg.]

I think this change should no longer be needed?  But it is also
harmless to keep.

------------------------------------------------------------------------------ 
src/share/vm/runtime/globals.hpp
2073   product(bool, ExecutingUnitTests, false,

This flag appears to only be referenced in debug builds, so why is it
a product flag rather than a develop flag?

------------------------------------------------------------------------------