NZSLC: Add precompiled binaries for options

[SirLynix]

One drawback of NZSL is its massive use of options, which prevent the early generation of GLSL and SPIR-V.

Something we could do to help with this is to give NZSLC (compiler) a set of options values that could be precompiled and embedded into a file (.nzslb? another file?).

For example:

[nzsl_version("1.0")]
module;

option HasDiffuseTexture: bool = false;
option HasAlphaTexture: bool = false;
option AlphaTest: bool = false;

option PosLocation: i32;
option UvLocation: i32 = -1;

We could imagine an additional file giving all options values to precompile:

{
    "targets": [
        {
            "type": "glsl",
            "version": 330
        },
        {
            "type": "glsl-es",
            "version": 330
        },
        {
            "type": "spv",
            "version": 100
        }
    ],
    "option_values": {
        "HasDiffuseTexture": [false, true],
        "HasAlphaTexture": [false, true],
        "AlphaTest": [false, true]
    },
    "variants": [
        {
            "options": {
                "ColorLocation": 0,
                "UvLocation": 1
            }
        },
        {
            "options": {
                "ColorLocation": 1,
                "UvLocation": 0
            }
        }
    ]
}

this would lead to the generation of 16 variations per shading language (so a total of 48 here), each variation would be associated with a hash of its option values.

Perhaps we could also give options a range of acceptable values:

[range(0,1)] option PosLocation: i32;
[range(0,1)] option UvLocation: i32 = -1;

which would allow NZSLC to know which variations are allowed without even a variant list file (however this could result in a lot of variations very quickly).

What do you think?