This reverts to following commits:
* rB5cad004d716da02f511bd34983ac7da820308676
* rB97e3a2d935ba9b21b127eda7ca104d4bcf4e48bd
* rBf60b95b5320f8d6abe6a629fe8fc4f1b94d0d91c
* rB0bd3cad04edf4bf9b9d3b1353f955534aa5e6740
* rBf72cc47d8edf849af98e196f721022bacf86a5e7
* rB3f7014ecc9d523997062eadd62888af5fc70a2b6
* rB0578921063fbb081239439062215f2538a31af4b
* rBc20098e6ec6adee874a12e510aa4a56d89f92838
* rBd5efda72f501ad95679d7ac554086a1fb18c1ac0
The original move to c++ that the other commits depended upon had some issues
that should be fixed before committing it again. The issues were reported in
T93797, T93809 and T93798.
We should also find a better rule for not using c-style casts going forward,
although that wouldn't have been reason enough to revert the commits.
Introducing something like a `MEM_new<T>` and `MEM_delete<T>`
function might help with the the most common case of casting the return
type of `MEM_malloc`.
Going forward, I recommend first committing the changes that don't
require converting files to c++. Then convert the shading node files
in smaller chunks. Especially don't mix fairly low risk changes like
moving some simple nodes, with higher risk changes.
This will be useful in the future to use the new socket builder API
Aditional changes:
- Declare variables where initialized
- Do not use relative includes
Differential Revision: https://developer.blender.org/D13465