Update REPLMode.jl for faster startup

[PallHaraldsson]

Fixes 3x PythonCall startup regression because of: JuliaPy/CondaPkg.jl#145 (at least least if backported to 1.11).

$ julia +1.11 --compile=min

julia> @time Pkg.REPLMode.gen_help()
  0.180643 seconds (91.88 k allocations: 2.218 MiB, 17.97% compilation time)

vs.
julia> @time Pkg.REPLMode.gen_help()
  2.129547 seconds (871.64 k allocations: 44.875 MiB, 5.32% gc time, 99.94% compilation time)

That one function slows down CondaPkg, and therefore also PythoCall, by that amount on 1.11

[PallHaraldsson]

I think I can only selectively change opt for a module, not one function. That's the one I care about, do you think any of the others are speed-critical?

[KristofferC]

What version are you on? This is for me:

julia> VERSION
v"1.11.0-rc3"

julia> using Pkg

julia> @time Pkg.REPLMode.gen_help()
  0.000287 seconds (2.50 k allocations: 134.836 KiB)
  Welcome to the Pkg REPL-mode. To return to the julia>
...

[PallHaraldsson]

I was working on 1.11.0-rc3. Make sure to test in the REPL without ever opening the Pkg mode (or not in the REPL).

However, I'll likely abandon this (draft) and try to get Pkg faster, rather avoid depending on it.