Fix D3D8, D3D9, and GL builds.

Bug swiftshader:63
Bug swiftshader:31

Change-Id: I59d08cbc8379e2c30984b9ec0ed4d49317633ce8
Reviewed-on: https://swiftshader-review.googlesource.com/10048
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
diff --git a/src/D3D8/Direct3DVertexShader8.hpp b/src/D3D8/Direct3DVertexShader8.hpp
index 046f7b4..388bca0 100644
--- a/src/D3D8/Direct3DVertexShader8.hpp
+++ b/src/D3D8/Direct3DVertexShader8.hpp
@@ -29,12 +29,12 @@
 	public:
 		Direct3DVertexShader8(Direct3DDevice8 *device, const unsigned long *declaration, const unsigned long *shaderToken);
 
-		virtual ~Direct3DVertexShader8();
+		~Direct3DVertexShader8() override;
 
 		// IUnknown methods
-		long __stdcall QueryInterface(const IID &iid, void **object);
-		unsigned long __stdcall AddRef();
-		unsigned long __stdcall Release();
+		long __stdcall QueryInterface(const IID &iid, void **object) override;
+		unsigned long __stdcall AddRef() override;
+		unsigned long __stdcall Release() override;
 
 		// Internal methods
 		const sw::VertexShader *getVertexShader() const;