libjpeg-turbo: Improve config files and fix patches

[akien-mga]

Fixing a few minor issues with the libjpeg-turbo config:

• My previous sync libjpeg-turbo: Update to 3.1.3 #113945 missed updating some hardcoded version numbers
• The default BUILD is the date of generating the config, I replaced it with "Godot" (it's used in an info string)
• Define NO_PUTENV/NO_GETENV, they're only used for niche environment variable hacks to override the SIMD CPU support (which we don't enable anyway) or the default memory manager's max memory.
• Simplify and improve the HIDDEN and INLINE defines for the 21st century.
• Set HAVE_INTRIN_H for MSVC.

CC @DanielKinsman

[DanielKinsman]

Looks fine to me, sorry for making it a bit of a burden to update with the cmake conversion and patch stuff. I wonder if we could just use cmake in the build process and then use the library files it generates, or at least the headers... that is probably more painful than what we have now though and I guess we hopefully don't need to update it that often.

[akien-mga]

Using CMake would be a net negative here IMO, as it would add a dependency, and in my experience CMake is a pain for cross-compilation (at least for the kind of advanced cross-compilation needs we have). We're also not building for the host platform (what CMake does) but for a target which may have different capabilities, even on the same OS family or architecture. (E.g. compiling on a Linux machine that supports AVX but we want to limit ourselves to SSE4.2.) So making explicit decisions in our config is better IMO.

It's not too much burden here and should indeed not change too much in the future, I just messed up my last sync. The main burden is the hardcoded 3.1.3 we'll have to remember to update each time, but the rest of the config probably won't change (it seems designed to cater to 30 year old architectures and compilers so I'm not too worried that this code changes every release :P).

On the other hand we could maybe remove the 0001 patch and just commit the files as is, documenting that they should be diffed occasionally against a CMake-generated one to see if we're missing things. Having files created by the patch makes the patch regeneration a bit more complex than usual with Git.

Edit: Hm no let's keep them as a patch, it's easier to restore them on update.

[Calinou]

Code looks good to me.

[Repiteo]

Thanks!