LINUX: Apply ignoreAddr filter only if PC set
LINUX: Apply ignoreAddr filter only if PC set

If ignoreAddr option is used to filter-out crashes close to 0x0,
some crashes might get lost when target crashed with a fatal
stack corruption (e.g. pc=0x0, si.addr=0x0, filter will wrongly
skip the crash).

This commit fixes the bug by ensuring that PC reg is always
set, before applying the ignoreAddr filter.

Signed-off-by: Anestis Bechtsoudis <7611fa5e9fd33f993ed88a8464a47644a6f066ca@census-labs.com>

riusksk/riufuzz,google/honggfuzz,riusksk/riufuzz,google/honggfuzz,riusksk/riufuzz,riusksk/riufuzz,riusksk/riufuzz,riusksk/riufuzz,riusksk/riufuzz,google/honggfuzz,anestisb/honggfuzz