add support for tracing process stacks in ddb (trace /p). due to the way arguments are parsed, pid has to be specified in the hexadecimal notation.
add support for tracing process stacks in ddb (trace /p).
due to the way arguments are parsed, pid has to be specified
in the hexadecimal notation.

tested by me and sthen,  ok sthen kettenis

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars