This merges the instantiation logic between instantiateModule
and instantiateModuleFromAsm.

BUG= https://code.google.com/p/v8/issues/detail?id=4203
TEST=asm-wasm
R=aseemgarg@chromium.org,titzer@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1581913005

Cr-Commit-Position: refs/heads/master@{#33316}