Function flushGlError

3rdparty/bgfx/src/renderer_gl.cpp:1168–1171

	typedef void (*PostSwapBuffersFn)(uint32_t _width, uint32_t _height);

	void flushGlError()
	{
		for (GLenum err = glGetError(); err != 0; err = glGetError() );
	}

	GLenum getGlError()
	{