RFR(S) : 8183337 : hotspot/compiler/aot tests fail due to missed tools

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev//8183337/webrev.00/index.html
> 226 lines changed: 160 ins; 62 del; 4 mod; 


Hi all,

could you please review this small patch which aims to solve the problem w/ missed linker in aot tests?

problem: jaotc tool needs linker to be installed, but at some hosts, esp. windows and mac, it is not always a case. as a results, aot tests which use jaotc fail on such hosts.
fix: on hosts which don't have 'ld' in PATH, we download the devkit and pass the path to the linker from it to jaotc tool.
caveats: 
 - oracle implementation of artifacts resolver does not work concurrently, so the tests have to be run in 'exclusiveAccess' mode
 - some devkits (linux, solaris) are applicable only for a specific OS version

bug: https://bugs.openjdk.java.net/browse/JDK-8183337
webrev: http://cr.openjdk.java.net/~iignatyev//8183337/webrev.00/index.html
testing: hotspot/compiler/aot on all platforms including systems w/o installed linker

Thanks,
-- Igor