Includes the fix for invalid SPIR-V merge blocks.
Removed the temporary patch added in e75a1838.

Change-Id: Ibab6c3606077a4b7207884d24bbf1232207d1800
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/40128Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Ben Clayton <bclayton@google.com>