RFR(XXS) 8198845: Missing resource mark results disassembling generated code failure in hs error report

[Zhengyu Gu]

nmethod uses stringStreams to buffer contents. Missing resource mark 
during error reporting, results failures while disassembling nmethod code.

Bug: https://bugs.openjdk.java.net/browse/JDK-8198845
Webrev: http://cr.openjdk.java.net/~zgu/8198845/webrev.00/

Test:

   hotspot_runtime on Linux x64 (fastdebug + release)

Thanks,

-Zhengyu