RFR: 8204551: Event descriptions are truncated in logs

[Yasumasa Suenaga]

Hi,

I posted the issue that some log messages in hs_err and VM.info are truncated.

  https://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2018-June/028410.html

I've had some discussion about it on JBS, and I uploaded webrev for it.
I use THIS_FILE macro for internal exceptions, and I expanded to 512 bytes
for capacity of internal exception.
It has passed submit repo tests. Could you review it?

  JBS: https://bugs.openjdk.java.net/browse/JDK-8204551
  webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8204551/webrev.02/


Thanks,

Yasumasa