Add support for using doubles in the LUA53 build.

[pjsg]

Fixes #3224.

• This PR is for the dev branch rather than for master.
• This PR is compliant with the other contributing guidelines as well (if not, please describe why).
• I have thoroughly tested my contribution.
• The code changes are reflected in the documentation at docs/*.

This brings back support for using doubles as the floating point format in the LUA53 build. This makes it much more compatible with the old LUA51 firmware.

[HHHartmann]

Some minor nitpicks but in general I think this is a good idea

[TerryE]

See comments on #3224. The Lua VM evaluates integer expressions using the default (sint32) type. Adding doubles alone will work in a very counter intuitive way for developer familiar with the 5.1 VM behaviour.

[pjsg]

This version changes the option for a build to be double & 64-bit ints. In retrospect, I should have done this first time around.

[pjsg]

@HHHartmann I think that I have addressed all your issues.

[marcelstoer]

@nwf @pjsg as discussed, ok for you if we land this immediately after the next master drop (~1 week from now)?

[pjsg]

Sounds good to me.

…

On Sun, Oct 25, 2020, 07:53 Marcel Stör ***@***.***> wrote: @nwf <https://github.com/nwf> @pjsg <https://github.com/pjsg> as discussed, ok for you if we land this immediately after the next master drop (~1 week from now)? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#3225 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AALQLTOE6OHFQHMLBSKEWMDSMQGTZANCNFSM4PALZARQ> .