shader int bit widths: restrict to 32 bits #229
Description
In vanilla Vulkan, integer scalars must be 32-bit.
shaderInt16 is an optional feature in Vulkan 1.0
shaderInt64 is an optional feature in Vulkan 1.0
shaderInt8 is an optional feature introduced by extension VK_KHR_float16_int8
For widest availability, the WebGPU shader programming model should be restricted to 32-bit ints.