fix #17046, deprecate tic and toc

[JeffBezanson]

Base exports roughly 9 identifiers related to timing code, which I think is quite a lot, especially when BenchmarkTools.jl offers better functionality. So I think these are pretty redundant and can be removed.

[giordano]

If @belapsed from BenchmarkTools.jl worked at all in Julia master that would be useful, yes. Unfortunately, it's currently broken. (Well, besides that issue, most of the package is currently broken on Julia master.)

[KristofferC]

As a workaround, you can use

b = @benchmarkable 1+1
tune!(b)
run(b)