The {GetNearRuntimeStubEntry} and {GetNearCallTargetForFunction}
functions need to find the code space that contains the current
function. This lookup requires a lock and is non-trivial. The repeated
lookup caused severe regressions.

This CL introduces a {JumpTablesRef} struct which holds information
about the jump tables to use. It can be looked up once and then used
for a whole function or even several functions within the same code
space (in {NativeModule::AddCompiledCode} which adds a whole vector of
compilation results).

This fixes the regressions.

R=ahaas@chromium.org

Bug: chromium:1004262, v8:9477
Change-Id: I50bd8327a131e3bee79d86b6d7e867a506959312
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1840153
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64129}