glslangValidator does not output an error when gl_WorkGroupSize is used before layout(local_size*=...)

[KonstantinSeurer]

The glsl spec states

It is a compile-time error to use gl_WorkGroupSize in a shader that does not declare a fixed
workgroup size, or before that shader has declared a fixed workgroup size, using local_size_x,
local_size_y, and local_size_z.

As of version 11:15.1.0, glslangValidator silently replaces the gl_WorkGroupSize with ivec3(1, 1, 1) instead of printing an error which can cause issues that are hard to debug.