Fix the slice check. Close gh-184.
Fix the slice check. Close gh-184.

As of 9751a47ded9693140af2aa635f7a9d928ac30a0b, docElem is not defined
at the point of its use in the slice check, so it always fails, and the
native slice never gets used.

npmcomponent/cristiandouce-sizzle,mzgol/sizzle