Deferred function call validation is required to support out of order
asm.js function declaration. Unfortunately, since we've started interleaving
validation and asm-wasm building, we don't check names are resolved until
the end.
Fortunately, undefined names can be detected from their CallType.
Check this at asm-typer time.

BUG=676797
R=aseemgarg@chromium.org,titzer@chromium.org

Review-Url: https://codereview.chromium.org/2615443003
Cr-Commit-Position: refs/heads/master@{#42158}