Naga produces a reserved keyword when translating variable name `packed` to GLSL

Description

The following fragment of a WGSL shader:

fn unpack_components(packed: u32) -> vec2<u32> {
    return vec2<u32>(packed >> 8u, packed & 15u);
}

(Full shader: https://github.com/ruffle-rs/ruffle/blob/036839fb1f382852711e0c1e270fa3e69a3a540a/render/wgpu/shaders/filter/displacement_map.wgsl)

sometimes fails with error: syntax error, unexpected PACKED_TOK, expecting ')' (Linux) or 'packed' : reserved word ERROR: 0:42: 'packed' : syntax error syntax error (Windows) on Open GL.

Repro steps

Use a variable packed in a WGSL shader and try to compile it using Open GL backend on a device where packed is a reserved keyword (I have no idea when packed is a keyword, it works for some people, for some doesn't).

Expected vs observed behavior

The shader should always work without syntax errors.

Extra materials

Bugs reported for Ruffle with this issue: https://github.com/ruffle-rs/ruffle/issues/12844, https://github.com/ruffle-rs/ruffle/issues/16642.

A screenshot pasted at Ruffle's Discord:

My workaround that turned out to work:

https://github.com/ruffle-rs/ruffle/pull/16805

Platform

I personally cannot reproduce it as Open GL does not work on my platform, but platform information is included in the issues referenced above.

gfx-rs / wgpu

Naga produces a reserved keyword when translating variable name `packed` to GLSL #5853