Remove unreasonably slow alternatives to lodash functions

[valadaptive]

I haven't comprehensively looked over the list of alternatives, but just as an example, one of the listed alternatives to _.last(numbers) is:

[].concat(numbers).pop()

It is even listed twice since it "works with undefined/null":

// Native (works even with potentially undefined/null)
[].concat(undefined).pop()

While this code is certainly clever, it's also slow. It creates an entire copy of the source array in memory, and if someone uses this code in a loop, it could easily go quadratic.

I believe that code like this which "prematurely pessimizes" common operations should not be listed as an example.