The {SetTraceValue} method was only defined for a set of integer types,
which sometimes lead to ambiguities when using types like {size_t},
{unsigned long} or the like (see https://crrev.com/c/1886912/1).
This CL fixes that by providing a method accepting any integer type.
It also changes the existing methods to avoid the "cast via union"
idiom, and uses memcpy instead.

R=petermarshall@chromium.org

Bug: v8:9810
Change-Id: I1530405640dc6cb0058153a8dbb860c7f3727ac5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1886918
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64710}