Port 3cad6bf5

Original Commit Message:

    This is a reland of c7c47c68.

    This makes TSAN happy in addition to:

    Previously I presumed that the context read from a frame in the profiler was
    a valid context. Turns out that on non-intel we're not guaranteed that the
    frame is properly set up. In the case we looked at, the profiler took a
    sample right before writing the frame marker indicating a builtin frame,
    causing the "context" pointer from that frame to be a bytecode array. Since
    we'll read random garbage on the stack as a possible context pointer, I made
    the code reading the native context from it a little more defensive.

    Bug: v8:9860
    Tbr: ulan@chromium.org, neis@chromium.org, ishell@chromium.org

    Original change's description:
    > [runtime] Move Context::native_context to the map
    >
    > Remove the native context slot from contexts by making context maps
    > native-context-specific. Now we require 2 loads to go from a context to the
    > native context, but we have 1 field fewer to store when creating contexts.
    >
    > Change-Id: I3c0d7c50c94060c4129db684f46a567de6f30e8d
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1859629
    > Commit-Queue: Toon Verwaest <verwaest@chromium.org>
    > Reviewed-by: Igor Sheludko <ishell@chromium.org>
    > Reviewed-by: Peter Marshall <petermarshall@chromium.org>
    > Reviewed-by: Maya Lekova <mslekova@chromium.org>
    > Reviewed-by: Georg Neis <neis@chromium.org>
    > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
    > Reviewed-by: Toon Verwaest <verwaest@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#64296}

R=xwafish@gmail.com

Change-Id: I6496a8c5be8cbabf48cddc2d59111410f31eb75f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1868774
Auto-Submit: Mu Tao <pamilty@gmail.com>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64486}