RFR:

[Erik Helin]

Hi all,

this patch changes the output directory for hotspot's jtreg tests when
run via the top-level Makefile targets such as
`make test-hotspot-jtreg`.

The current directory is
<top-level>/build/<conf>/hotspot/linux-x64/testoutput
(on an x86-64 machine running Linux). There is no need to place the
"testoutput" directory in a directory which name is based on OS and arch,
that is already done by the current configuration. Therefore, we can
instead place the "testoutput" directory in
<top-level>/build/<conf>/hotspot/, which is a more reasonable location
for the output from hotspot's tests.

Enhancement:
https://bugs.openjdk.java.net/browse/JDK-8146985

Webrev:
http://cr.openjdk.java.net/~ehelin/8146985/00/webrev

Testing:
- Running `make test-hotspot-jtreg` locally
- JPRT (the patch does not affect JPRT since JPRT does not use
  ALT_OUTPUTDIR)

Thanks,
Erik