cmd/compile: fix FP accuracy issue introduced by FMA optimization on ARM64

cmd/compile: fix FP accuracy issue introduced by FMA optimization on ARM64

Two ARM64 rules are added to avoid FP accuracy issue, which causes
build failure.
https://build.golang.org/log/1360f5c9ef3f37968216350283c1013e9681725d

fixes #24033

Change-Id: I9b74b584ab5cc53fa49476de275dc549adf97610
Reviewed-on: https://go-review.googlesource.com/96355
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>