Following #1721, there is an issue uncovered that making the binding numbers implicit would effectively require all the implementations to do binding re-mapping. This re-mapping can only be done at pipeline creation time, and thus precludes creating SPIR-V shader modules earlier.

Thinking about a compromise, we could say that binding numbers are limited to 65535 (similar to the overridable constant indices). This should allow a non-remapping implementation to reason about binding numbers at shader module creation time.