This is a follow-up to https://chromium-review.googlesource.com/981687.

When a wasm function has a large stack frame, the x64 code generator
performs the stack overflow check before constructing the frame. This
requires the use of the `address_of_real_stack_limit` external
reference.

This reference is thread local, so if it is not relocated the stack
overflow check will always fail.

Bug: chromium:808848
Change-Id: I0edf3fe5a006242fc50d0bff44cd9dd0e7d85bd9
Reviewed-on: https://chromium-review.googlesource.com/982906
Commit-Queue: Ben Smith <binji@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52330}