[dev.simd] cmd/compile, simd: added methods for "float" GetElem
This also required a "always use operation with least
OverrideBase" filter in choosing the machine instructions.
The order of generated HW operations is slightly
modified because the Float version of GetElem
appears earlier in the sorted operations list,
though it is not chosen to generate the HW Op.
Change-Id: I95fa67afca9c8b6f4f18941fdcaf69afdad8055b
Reviewed-on: https://go-review.googlesource.com/c/go/+/696375 Reviewed-by: Junyang Shao <shaojunyang@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com>