Upstream Emscripten changed this in 1.39.1+, so IDBFS is no longer
included by default and has to be linked manually.
The explicit linking doesn't seem to be problematic on earlier
versions (tested `1.38.47-upstream`).
Fixes#33724.
(cherry picked from commit e5dfcb5edd)
A change in upstream Emscripten 1.39.1+ made our buildsystem error
out where it was previously only issuing a warning:
```
[ 5%] Linking Static Library ==> main/libmain.javascript.opt.bc
shared:WARNING: Assuming object file output in the absence of `-c`, based on output filename. Please add with `-c` or `-r` to avoid this warning
Ranlib Library ==> main/libmain.javascript.opt.bc
/opt/emsdk/upstream/bin/llvm-ranlib: error: unable to load 'main/libmain.javascript.opt.bc': file too small to be an archive
```
As advised on emscripten-core/emscripten#9806, we should be using
`emar` here to create the static library and not `emcc`.
This was apparently done to workaround Emscripten issues in the past,
but evidently this is no longer necessary.
The rest of the `env` redefinitions should probably be re-assessed
against the current state of Emscripten.
Fixes#33374.
(cherry picked from commit e9e2a4b044)
The code in pre.js and engine.js is a bit confusing to see in isolation,
since the files aren't valid JS files by themselves. This just adds some
explanatory text to both files.
Fixes#22937.
(cherry picked from commit 61d5513525)
Now generating mouse events from touch is optional (on by default) and it's performed by `InputDefault` instead of having each OS abstraction doing it. (*)
The translation algorithm waits for a touch index to be pressed and tracks it translating its events to mouse events until it is raised, while ignoring other pointers.
Furthermore, to avoid an stuck "touch mouse", since not all platforms may report touches raised when the window is unfocused, it checks if touches are still down by the time it's focused again and if so it resets the state of the emulated mouse.
*: In the case of Windows, since it already provides touch-to-mouse translation by itself, "echo" mouse events are filtered out to have it working like the rest.
On X11 a little hack has been needed to avoid a case of a spurious mouse motion event that is generated during touch interaction.
Plus: Improve/fix tracking of current mouse position.
Using `misc/scripts/fix_headers.py` on all Godot files.
Some missing header guards were added, and the header inclusion order
was fixed in the Bullet module.
