* Port over new code tables from Cycles
* Convert Rec.709 to scene linear for lookup table.
* Move code for wavelength and blackbody to IMB so they can access the
required transforms, which are not in blenlib.
* Remove clamping from blackbody shader to bypass the texture read.
Since it's variable now easiest to just always read from the texture
than pass additional parameters.
* Fold XYZ to RGB conversion into the wavelength table.
Ref T68926
This patch continue the efforts to split the `gpu_shader_material` file
started in D5569.
Dependency resolution is now recursive. Each shading node gets its own
file. Additionally, some utility files are added to be shared between
files, like `math_util`, `color_util`, and `hash`. Some files are always
included because they may be used in the execution function, like
`world_normals`.
Some glsl functions appeared to be unused, so they were removed, like
`output_node`, `bits_to_01`, and `exp_blender`. Other functions have
been renamed to be more general and get used as utils, like `texco_norm`
which became `vector_normalize`.
A lot of the opengl tests fails, but those same tests also fail in
master, so this is probably unrelated to this patch.
Reviewers: brecht
Differential Revision: https://developer.blender.org/D5616
