Do not emit double values at their use sites.

Do not emit double values at their use sites.

Revert part of r14179. From the regression test's comment:

Currently, the gap resolver doesn't handle moves from a ConstantOperand to a
DoubleRegister, but these kind of moves appeared when HConstant::EmitAtUses
was changed to allow special double values (-0, NaN, hole). So we should
either enhance the gap resolver or make sure that such moves don't happen.

BUG=chrome:234101

Review URL: https://codereview.chromium.org/14429002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14394 ce2b1a6d-e550-0410-aec6-3dcde31c8c00