Add missing operation.
Add missing operation.

Bug 27227050

Change-Id: Id8b6357f25888801dec9bbedc5855faa58def62d
Reviewed-on: https://swiftshader-review.googlesource.com/4920
Reviewed-by: Nicolas Capens <0612353e1fcebbfd4b302d9337447ca0cdfa9122@google.com>
Tested-by: Daniel Toyama <d26f245d6be4eed80f1a94e9bfc77e076539430c@google.com>

google/swiftshader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,google/swiftshader,bkaradzic/SwiftShader,google/swiftshader