RFR(S): 8151707: Mark hotspot tests which ignore external VM flags

[Dmitry Fazunenko]

Hello,

Could you review a simple fix with introduces a new jtreg keyword: 
"noflags".
The purpose of this keyword is to mark those tests which ignore VM flags 
given outside (on the command line).
It will allow to not run such tests many times in different VM 
configurations as we do every night,
but run only once.

Note: this fix will not affect execution, so the tests labeled as 
"noflags" will not be automatically
filtered out in case of external VM flags are given. It will just allow 
to not execute such tests:
   # jtreg  -k:'!noflags' -vmflags:'-XX:+UseG1GC -Xint' test/

Note2: All the tests modified tests are manually reviewed to be sure 
that they indeed ignore external VM flags.

https://bugs.openjdk.java.net/browse/JDK-8151707
http://cr.openjdk.java.net/~dfazunen/8151707/webrev.01/

Thanks,
Dima