tsc: use cpuid 0x16 to get tsc frequency in some cases by sporksmith · Pull Request #3736 · shadow/shadow

@sporksmith

Also unconditionally get and report relevant cpuid info for bug
reporting.

Make more use of `const` since the points of initialization are a
bit separated from points of use.

robgjansen

@sporksmith

Our lists of other cpu id's that don't specify a core frequency has been
shown to be incomplete, so we can't safely guess Intel Core by process
of elimination.