Blender Git Loki

Python: gpu module: add new submodules and types

This commit extends the gpu python API with:
```
gpu.types.Buffer #"__init__", "to_list"
gpu.types.GPUTexture #"__init__", "clear", "read", "format"
gpu.types.GPUFrameBuffer #"__init__", "bind", "clear", "is_bound", "viewport", ("__enter__", "__exit__" with "GPUFrameBufferStackContext")
gpu.types.GPUUniformBuf #"__init__", "update"
gpu.state #"blend_set", "blend_get", "depth_test_set", "depth_test_get", "depth_mask_set", "depth_mask_get", "viewport_set", "viewport_get", "line_width_set", "line_width_get", "point_size_set", "color_mask_set", "face_culling_set", "front_facing_set", "program_point_size_set"
```

Add these methods to existing objects:
```
gpu.types.GPUShader #"uniform_sample", "uniform_buffer"
```

Maniphest Tasks: T80481

Differential Revision: https://developer.blender.org/D8826

BLI: add BLI_simd.h header to wrap SSE includes

In preparation of adding Neon support.

Ref D8237, T78710

BLI: use sse2neon to emulate SSE instructions with Arm Neon

* WITH_CPU_SSE was renamed to WITH_CPU_SIMD, and now covers both SSE and Neon.
* For macOS sse2neon.h is included as part of the precompiled libraries.
* For Linux it is enabled if the sse2neon.h header file is detected. However
this library does not have official releases and is not shipped with any Linux
distribution, so manual installation and configuration is required to get this
working.

Ref D8237, T78710

Cycles: refactor intrinsic functions implementation

* Add processor independent fallbacks
* Use uint32_t and uint64_t types
* Remove unused functions
* Better comments and less indentation

Ref D8237, T78710

Cycles: add utility functions for zero float2/float3/float4/transform

Ref D8237, T78710

Cycles: add support for Arm Neon instructions using sse2neon

Based on patch contributed by Apple and Stefan Werner.

Ref D8237, T78710

Fix T85694: Cycles incorrect grayscale conversion with some OpenColorIO configs

Cleanup: fix compiler warnings

Merge branch 'blender-v2.92-release'

Cleanup: Missing word in rna description

One of the sentences changed recently in rBc63df3b33f01 was missing
a word. No functional changes.

Merge branch 'blender-v2.92-release'

Fix T85722: missing updates adding modifiers via python

Was reported for Geometry Nodes Editor "New" button, but was true for
any modifier added via modifiers.new().

Now just add appropriate nofifier.

Maniphest Tasks: T85722

Differential Revision: https://developer.blender.org/D10450

Merge branch 'blender-v2.92-release'

Cleanup: Split COM_compositor into multiple functions.

Geometry Nodes: Expose material index attribute

The `material_index` attribute can adjust which material in the list
will be applied to each face of the mesh. There are two new things
about this attribute that haven't been exposed by the attribute API yet.
Each comes with limitations:
1. Integer data type: Most attribute nodes are currently written to use
float data types. This means that they can't write to this attribute
because they can't change the type of a built-in attribute.
2. Polygon domain: This is our first attribute using the polygon domain,
meaning until some of the interpolations are implemented, some
operations may not work as expected.

Currently the two nodes that work with this attribute are Attribute Fill
and Attribute Randomize.

Differential Revision: https://developer.blender.org/D10444

Cleanup: Make ChunkOrder a struct.

Cleanup: Make ChunkOrderHotspot a struct

Cleanup: Allocate Execution System on stack.

Cleanup: Comment style

Cleanup: Bundle static globals in struct