We use a signaling NaN to represent the hole in
FAST_HOLEY_DOUBLE_ELEMENTS backing stores, but on Intel processors, the
C++ compiler may decide to (or be forced to due to calling conventions)
use X87 registers for double values. However transfering to X87
registers automatically quietens the NaNs and there's no way to disable
this. Therefore we should just always load the hole NaN from the canonical
place identified by the address_of_hole_nan external reference instead,
which might even be more efficient in some cases.
R=jarin@chromium.org, jkummerow@chromium.org
BUG=v8:5332
Review-Url: https://codereview.chromium.org/2303643002
Cr-Commit-Position: refs/heads/master@{#39062}
