Port d4a391bb

Add SmiTag()/smiUntag() calls to make values on stack GC-safe.

Original commit message:
Use macro instructions for min, max ops to get the same functionality on
pre-r6 and r6 targets.

BUG=chromium:598651
LOG=N

Review URL: https://codereview.chromium.org/1842833002

Cr-Commit-Position: refs/heads/master@{#35130}