The interpreter is set up specially in cctests to allow more direct
testing. This requires sometimes to write special testing code in the
interpreter which is different than production code. This CL fixes one
instance of testing code which deals with indirect calls.

In production code, indirect calls go through the indirect function
table which can change over time. In cctests, however, the indirect
function table is not set up completely. In cctests the interpreter
uses information from the module instead to acquire the target of an
indirect call. In that testing code, calls to imported JS functions
were not handled. This handling gets added with this CL.


CC=fgm@chromium.org
R=titzer@chromium.org

Bug: v8:7431
Change-Id: I3b90d4ea8fec2633c010dd8359814440c7988509
Reviewed-on: https://chromium-review.googlesource.com/c/1495560Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59965}