IGPUShader: add setShaderStage method

Signed-off-by: Ali Cheraghi <alichraghi@proton.me>

Author: alichraghi

include/nbl/video/IGPUShader.h

@@ -24,6 +24,11 @@ class IGPUShader : public asset::IShader, public IBackendObject
     public:
         using SSpecInfo = asset::IShader::SSpecInfo<const IGPUShader>;
 
+		void setShaderStage(const E_SHADER_STAGE stage)
+		{
+			m_shaderStage = stage;
+		}
+
     protected:
         explicit IGPUShader(core::smart_refctd_ptr<const ILogicalDevice>&& dev, const IShader::E_SHADER_STAGE shaderStage, std::string&& filepathHint)
             : IBackendObject(std::move(dev)), IShader(shaderStage, std::move(filepathHint)) {}