We were passing arrays by value which the compiler fails to optimize,
causing abyssal performance. To fix this, we need to consider that
descriptors can be in constant or const device address spaces.
Also, lone descriptors are passed by value, so we explicitly remove address
space qualifiers.
One failure case is when shader passes a texture/sampler array as an
argument. It's all UniformConstant in SPIR-V, but in MSL it might be
thread, const device or constant, so that won't work ...
Global variable use works fine though, and that should cover 99.9999999%
of use cases.
We used to use the Binding decoration for this, but this method is
hopelessly broken. If no explicit MSL resource remapping exists, we
remap automatically in a manner which should always "just work".
Support flattening StorageOutput & StorageInput matrices and arrays.
No longer move matrix & array inputs to separate buffer.
Add separate SPIRFunction::fixup_statements_in & SPIRFunction::fixup_statements_out
instead of just SPIRFunction::fixup_statements.
Emit SPIRFunction::fixup_statements at beginning of functions.
CompilerMSL track vars_needing_early_declaration.
Pass global output variables as variables to functions that access them.
Sort input structs by location, same as output structs.
Emit struct declarations in order output, input, uniforms.
Regenerate reference shaders to new formats defined by above.
