Assume SSE2 support is available.
Assume SSE2 support is available.

Chrome and many other products require SSE2 support as a minimum. Note
that MMX checks are left in place for now. Dead code paths are removed.

Bug swiftshader:78

Change-Id: Iabd8b1dc2092949d5dba29a78e75d014e808f12c
Reviewed-on: https://swiftshader-review.googlesource.com/11068
Tested-by: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>
Reviewed-by: Alexis Hétu <1c7141772178a7e80858c3db5052b328076f08f4@google.com>
Reviewed-by: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>

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