Match sub-vector load/store operand order to regular load/store.
Match sub-vector load/store operand order to regular load/store.

BUG=swiftshader:15

Change-Id: If608ab4903d97daa0ad342d02f496ac3fa6471d9
Reviewed-on: https://chromium-review.googlesource.com/414389
Reviewed-by: Jim Stichnoth <46a13f57ad465cec7f48cfe1a20c394bb659ab25@chromium.org>

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