By now the compiler pipeline will not produce optimized code for asm.js
functions unless validation failed (even when --always-opt is enabled).
The related workaround in the testing predicate can be removed.

R=rmcilroy@chromium.org

Review-Url: https://codereview.chromium.org/2549463002
Cr-Commit-Position: refs/heads/master@{#41614}