Several tools take a --target-env option to specify the SPIR-V
environment to use. They all use spvParseTargetEnv to parse
the user-specified string and select the appropriate spv_target_env
but all tools list only _some_ of the valid values in their help
text.
This change makes the help text construction automatic from the
full list of valid values, establishing a single source of truth
for the values printed in the help text. The new utility function
added allows its user to specify padding and wrapping constraints
so the produced strings fits well in the various help texts.
Signed-off-by: Kévin Petit <kpet@free.fr>
Implemented Vulkan-specific rules:
- OpTypeImage must declare a scalar 32-bit float or 32-bit integer type
for the “Sampled Type”.
- OpSampledImage must only consume an “Image” operand whose type has its
“Sampled” operand set to 1.
