Incorrect cached pipeline as GraphicsState not copy safe

[publicrepo]

If you have multiple pipelines where the only difference is color blend state, the pipeline cache may choose the wrong cached pipeline.
This is caused by GraphicsState hash being computed from a copy of the GraphicsState and GraphicsState not being copy safe. Specifically, the pAttachments member points to the wrong address on copy. Ideally it would always point to it's accompanied m_colorBlendAttachments[0].

One solution would be to add a copy ctor. However, since only a single copy is made, and that copy is only used by the hash function, we can simply fix the hash function.

In GraphicsState::GetHash()
Replace m_colorBlendState.pAttachments[i] with m_colorBlendAttachments[i]
eg.

        // NOTE: Copy of m_colorBlendState.pAttachments is incorrect. Use m_colorBlendAttachments instead, same as GetColorBlendAttachmentState()
        for (auto i = 0U; i < m_colorBlendState.attachmentCount; ++i)
        {
            cb->colorWriteMask = static_cast<uint32_t>(m_colorBlendAttachments[i].colorWriteMask);
            cb->blendEnable = m_colorBlendAttachments[i].blendEnable;
            cb->srcColorBlendFactor = static_cast<uint32_t>(m_colorBlendAttachments[i].srcColorBlendFactor);
            cb->dstColorBlendFactor = static_cast<uint32_t>(m_colorBlendAttachments[i].dstColorBlendFactor);
            cb->colorBlendOp = static_cast<uint32_t>(m_colorBlendAttachments[i].colorBlendOp);
            cb->srcAlphaBlendFactor = static_cast<uint32_t>(m_colorBlendAttachments[i].srcAlphaBlendFactor);
            cb->dstAlphaBlendFactor = static_cast<uint32_t>(m_colorBlendAttachments[i].dstAlphaBlendFactor);
            cb->alphaBlendOp = static_cast<uint32_t>(m_colorBlendAttachments[i].alphaBlendOp);
            ++cb;
        }