A lot of changes in spirv-opt output.
Some new invalid SPIR-V was found but most of them were not significant
for SPIRV-Cross, so just marked them as invalid.
Certain patterns with OpVectorShuffle (and probably others) will cascade
to so large, that they can cause OOM. After we have observed
force_recompile, don't spend unnecessary memory emitting code which will
never be used.