Add test for Unpack in Reactor
Add test for Unpack in Reactor

Test: New test passes
Bug: b/67106219
Change-Id: Ib21f73d312d39cf2b3aa15a11d2a207885a58978
Reviewed-on: https://swiftshader-review.googlesource.com/12828
Reviewed-by: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>
Tested-by: Casey Dahlin <a6ca20ccfc356663c1ea98204ebdaf202aef1697@google.com>

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