This CL introduces 6 tests that verify that the effects of a grow_memory
instruction executed inside a function are visible also from the caller of
the function.

The tests verify that:

 * the current_memory instruction returns the correct value after
 returning from a function that grew memory;

 * accessing a memory page that has been created inside a function does
 not trap in the caller;

 * when a function grows the memory and then store something in the grown
 memory, the caller always reads from the grown memory. This checks that
 the memory start address gets updated in the caller (the memory buffer
 could in fact be relocated by the grow_memory instruction).

These tests are implemented for direct and indirect function calls.

R=ahaas@chromium.org,clemensh@chromium.org

Change-Id: Iac8db0fa7a6dd6f530e090af5423fc165d87e863
Reviewed-on: https://chromium-review.googlesource.com/616150
Commit-Queue: Enrico Bacis <enricobacis@google.com>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47398}