[glsl-in] naga rejects .length() unconditionally

[SpaceCat-Chan]

minimal example:

#version 440 core

layout(std430, binding = 0) buffer something_buf {
    uint something[];
};

void main() {
    uint test = uint(something.length());
}

naga-cli rejects this with the following error

error: Expected Comma or RightParen, found LeftParen
  ┌─ minimal.comp:8:38
  │
8 │     uint test = uint(something.length());
  │                                      ^