chore(shadertools): Port fp64 tests to GLSL 3.00

[ibgreen]

For #

Background

• I am working on a PR that drops support for GLSL 1.00 as the source language for luma.gl shaders. I will motivate this more fully in that PR, but basically to support WebGPU we need to embrace uniform buffers, which in WebGL requires GLSL 3.00, so we might as well write all our shader code in GLSL 3.00.
• As I was porting GLSL 1.00 shaders and fragments in our source to GLSL 3.00, I came across the fp64 tests.
• After I ported them, I got 5 new failures, just for subtractions.
• Hoping this could be a clue for someone (GLSL 1.00 and GLSL 3.00 do something differently, different backends etc.)

Change List

• Modify fp64 test shader
• ignore the new failing test cases.

[donmccurdy]

After I ported [the fp64 tests], I got 5 new failures, just for subtractions.

That's a very interesting find! I added this to the webkit discussion, and added a demo:

https://fp64-arithmetic.donmccurdy.com/?operator=sum_fp64&lang=GLSL+3.0

On my (Apple M2) device, GLSL 3 affects the test results only when ANGLE's OpenGL backend is enabled. After switching to the Metal backend, results are consistent (with many failures) for both GLSL 1 and GLSL 3.

[ibgreen]

Looks like my Chrome chooses ANGLE by default so yes I believe that is the env in which I got these problems.