This fixes the problem that `SynchronizationContext.Current` would be null
during the call to `_EnterTree`, `_Ready` and the first call to `_Process` thus
the task continuations would be scheduled outside the main thread, which is unexpected and might lead to crashes.
With this change, task continuations are scheduled always on the main thread and so async/await can be used without any explicit synchronization, which is what is expected.
Fixes#18849
Replace float with real_t in most files, defined at the top of each file via using. Objects such as Vector3 now accept doubles as inputs, and convert to real_t internally. I've added default Vectors such as Vector3.Zero. Other misc C# improvements such as Mathf.RoundToInt(). Color continues to use float only because high precision is not needed for 8-bit color math and to keep things simple. Everything seems to compile and work fine, but testing is requested, as this is the first time I've ever contributed to Godot.
- Sometimes `StackFrame.GetMethod()` returns null (e.g.: latest frame of a `MissingMethodException`). Still not sure what to do with that frame (maybe skip it), but at least it no longer fails.
- Skip `CSharpLanguage::debug_get_current_stack_info()` if an error is printed from `GDMonoUtils::update_corlib_cache()`.
- Fix crash when calling `GDMonoUtils::print_unhandled_exception(exc)` if there is no ScriptDebugger attached.
Fixes#15468
Also improves the error messages if the string isn't hex, because saying that the color value is negative is just a side effect of the implementation and tells you nothing.
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.
- alloc_language_binding: Use strong GC handle as well for references. Fixes#15138
- Set the native instance field of Godot.Object to IntPtr.Zero when it's freed.
- Create weak handles without tracking resurrection (that was causing trouble). This means we have to call notification predelete before queueing a native Object for deletion, and use the MonoObject* passed by the finalizer because the weak GC handle target will return NULL at this point.
