port 89d8c57b (r36916)

  original commit message:
  Import base::ieee754::atan() and base::ieee754::atan2() from fdlibm and
  introduce Float64Atan and Float64Atan2 TurboFan operators based on those,
  similar to what we already did for Float64Log and Float64Log1p. Rewrite
  Math.atan() and Math.atan2() as TurboFan builtin and use the operators
  to also inline Math.atan() and Math.atan2() into optimized TurboFan functions.

BUG=

Review-Url: https://codereview.chromium.org/2093423003
Cr-Commit-Position: refs/heads/master@{#37262}