Removed sw::Rect from Renderer.

Bug b/126883332

Change-Id: I01ff418745c19739b4692c7cec56ae54fe91a8fc
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/27109Tested-by: Alexis Hétu <sugoi@google.com>
Presubmit-Ready: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>