ARB_gl_spirv: evaluate adding more linking validations
In general there isn't any need of validation for the SPIR-V shader. There are several quotes pointing it, the more clear is this one:
The OpenGL API expects the SPIR-V module to have already been validated, and can return an error if it discovers anything invalid in the module. An invalid SPIR-V module is allowed to result in undefined behavior.
fwiw, it is not required any intrastage or interstage validation. This basically follows the Vulkan way to do things. But there is a major difference with Vulkan. Vulkan has the Validation Layers while OpenGL not.
Right now the ARB_gl_spirv implementation does the minimum on relation to validation. Although that is technically correct, as mentioned, it would be good to evaluate if it would be good to add some extra validations. The quote before allows that. Perhaps just on debug mode?
It is worth to note that some proprietary drivers are doing some validation when linking SPIR-V modules.