runtime: print hex numbers with hex prefixes in traceback debug
If traceback fails, it prints a helpful hex dump of the stack.
But the hex numbers have no 0x prefix, which might make it
a little unclear that they are hex.
We only print two per line, so there is plenty of room for the 0x.
Print it, which lets us delete a custom hex formatter.
Also, in the translated <name+off> hints, print off in hex
(with a 0x prefix). The offsets were previously decimal, which
could have been confused for hex since none of the hex had
0x prefixes. And decimal is kind of useless anyway since the
offsets shown in the main traceback are hex, so you can't
easily match them up without mental base conversions.
Just print hex everywhere, clearly marked by 0x.
This CL is part of a stack adding windows/arm64
support (#36439), intended to land in the Go 1.17 cycle.
This CL is, however, not windows/arm64-specific.
It is cleanup meant to make the port (and future ports) easier.