crucible: Convert from glslc to glslang
This essentially reverts b5a52577, but it seems that glslangValidator has since become a little more friendly. Additionally, I used python tempfile module to simplify creating tempfiles with the required extensions.
One reason to revert to using glslangValidator is just to remove the additional shaderc/glslc dependency. An advantage of using glslangValidator is that the SPIR-V binary and assembly code can be generated with a single invocation of glslangValidator.
Acked-by: Jason Ekstrand jason@jlekstrand.net Signed-off-by: Jordan Justen jordan.l.justen@intel.com