Add CPU implementer and part to problem reports and logs

From https://github.com/DynamoRIO/dynamorio/issues/1698#issuecomment-742513024

Perhaps collect CPU implementer and CPU part from /proc/cpuinfo to identify the implementation? I have found the following very useful (and accurate) as a look-up table for CPU implementer and CPU part: https://github.com/bp0/armids/blob/master/arm.ids

The proposal is to add this to the report_dynamorio_problem() formatted output, as well as printing it in debug logs.