read-only storage binding in VS results in scary warning in MSL

[kyren]

I have a binding like this in a WGSL shader

@group(0) @binding(1) var<storage,read> particle_buffer: ParticleBufferReadonly;

when translated to MSL, it becomes this parameter to vs_main:

, device ParticleBufferReadonly& particle_buffer [[buffer(1)]]

which then results in this scary warning:

    program_source:277:22: warning: writable resources in non-void vertex function
    vertex vs_mainOutput vs_main(
                         ^
    program_source:282:34: note: writable buffer defined here
    , device ParticleBufferReadonly& particle_buffer [[buffer(1)]]
                                     ^

This seems related to this PR #1711

If I revert the part of the PR that changes the function to_msl_name back to:

            Self::Storage { access } if access.contains(crate::StorageAccess::STORE) => {
                Some("device")
            }
            Self::Storage { .. } => Some("constant"),

then the parameter to the vs_main function becomes:

, constant ParticleBufferReadonly& particle_buffer [[buffer(1)]]

and the warning disappears.

I'm not sure if the warning has an actual negative effect or not, it doesn't seem to yet but I'm still fixing other problems. I only noticed this because the shader was failing MSL compilation for a different reason.