RFR 8203292: Print non-default flags to the hs_err file

[René Schünemann]

Hi,

can I please get a review for the following change:

Bug: https://bugs.openjdk.java.net/browse/JDK-8203292
Webrev: http://cr.openjdk.java.net/~simonis/webrevs/2018/8203292

With this change, all flags with a non-default value will be printed
to the hs_error file.
While the hs_err file already contains the full command line parameters,
flags can also be changed by ergonomics or various serviceability tools.

Thank you,
Rene