shader: use Khronos definitions and simplify compiler ownership

src/graphics/shader/recompiler/backend/spirv/SpirvEmitter.h

@@ -9,8 +9,6 @@
 
 namespace Libs::Graphics::ShaderRecompiler::Spirv {
 
-void AnalyzeProgramRequirements(IR::Program& program);
-
 std::vector<uint32_t> EmitProgram(const IR::Program& program,
                                   ShaderStageInputInfo input_info);