[16] RFR(S): 8251458: Parse::do_lookupswitch fails with "assert(_cnt >= 0) failed"

[Tobias Hartmann]

Hi,

please review the following patch:
https://bugs.openjdk.java.net/browse/JDK-8251458
http://cr.openjdk.java.net/~thartmann/8251458/webrev.00/

We hit an assert in Parse::do_lookupswitch() because the "taken" counter for a lookupswitch branch
is negative. The problem is an overflow when converting an uint counter value > max_jint from
profile information to a jint.

The fix is to handle such overflows by simply limiting the counter value to max_jint.

Best regards,
Tobias