This backports the work in #7815 and the subsequent fixes in #8393
The following program now works as expected in this branch in both
release_debug and debug mode:
```gdscript
print(sqrt(-1))
print(sqrt(-1))
var simple1=asin(10.0)
var simple2=acos(10.0)
print(simple1)
print(simple2)
```
And successfully prints -nan 4 times
This fixes#9580 and fixes#8925
By adding some PRAY_* macros that encapsulate both the check and the returning of a null reference (UB).
Plus transient avoidance of the flood of warnings emitted by Clang when checking 'this' for NULL.
Plus explanation about the do-while(0) loop in some error macros.
That year should bring the long-awaited OpenGL ES 3.0 compatible renderer
with state-of-the-art rendering techniques tuned to work as low as middle
end handheld devices - without compromising with the possibilities given
for higher end desktop games of course. Great times ahead for the Godot
community and the gamers that will play our games!
(cherry picked from commit c7bc44d5ad)
-IMA-ADPCM support for samples, this means that sound effects can be compressed and use 4 timess less RAM.
-New 3D import workflow based on Wavefront OBJ. Import single objects as mesh resources instead of full scenes. Many people prefers to work this way. Just like the rest of the imported resources, these are updated in realtime if modified externally.
-Mesh resources now support naming surfaces. This helps reimporting to identify which user-created materials must be kept.
-Several fixes and improvements to SurfaceTool.
-Anti Aliasing added to WorldEnvironment effects (using FXAA)
-2D Physics bodies (RigidBody, KinematicBody, etc), Raycasts, Tilemap, etc support collision layers. This makes easy to group which objects collide against which.
-2D Trigger shapes can now also trigger collision reporting in other 2D bodies (it used to be in Area2D before)
-Viewport render target textures can now be filtered.
-Few fixes in GDscript make it easier to work with static functions and class members.
-Several and many bugfixes.
Rémi Verschelde
Hein-Pieter van Braam
Pedro J. Estébanez
Hubert Jarosz
George Marques
Juan Linietsky