RFR: JDK-8199197: Set _NT_SYMBOL_PATH when running tests on windows

[Erik Joelsson]

When running tests on Windows in a distributed environment we currently 
don't have access to debug symbols, which causes stack traces in hs_err 
files to be useless. When running local tests this works because the 
product under test was built on the same machine and the debug symbols 
are still available there. For this to work in distributed testing, we 
need to both provide the symbols bundle as well as setting up the 
_NT_SYMBOL_PATH environment variable to point to the correct 
directories. This patch does just that for both the old and new test 
makefiles. I have verified by running a modified jtreg test in Mach5 
that crashes hotspot and verified that the stack trace contains symbols.

Bug: https://bugs.openjdk.java.net/browse/JDK-8199197

Webrev: http://cr.openjdk.java.net/~erikj/8199197/webrev.01/

/Erik