cmd/compile, math: improve implementation of math.{Max,Min} on loong64

cmd/compile, math: improve implementation of math.{Max,Min} on loong64

Make math.{Min,Max} intrinsics and implement math.{archMax,archMin}
in hardware.

goos: linux
goarch: loong64
pkg: math
cpu: Loongson-3A6000 @ 2500.00MHz
         │  old.bench   │              new.bench              │
         │    sec/op    │   sec/op     vs base                │
Max         7.606n ± 0%   3.087n ± 0%  -59.41% (p=0.000 n=20)
Min         7.205n ± 0%   2.904n ± 0%  -59.69% (p=0.000 n=20)
MinFloat   37.220n ± 0%   4.802n ± 0%  -87.10% (p=0.000 n=20)
MaxFloat   33.620n ± 0%   4.802n ± 0%  -85.72% (p=0.000 n=20)
geomean     16.18n        3.792n       -76.57%

goos: linux
goarch: loong64
pkg: runtime
cpu: Loongson-3A5000 @ 2500.00MHz
         │  old.bench   │              new.bench              │
         │    sec/op    │   sec/op     vs base                │
Max        10.010n ± 0%   7.196n ± 0%  -28.11% (p=0.000 n=20)
Min         8.806n ± 0%   7.155n ± 0%  -18.75% (p=0.000 n=20)
MinFloat   60.010n ± 0%   7.976n ± 0%  -86.71% (p=0.000 n=20)
MaxFloat   56.410n ± 0%   7.980n ± 0%  -85.85% (p=0.000 n=20)
geomean     23.37n        7.566n       -67.63%

Updates #59120.

Change-Id: I6815d20bc304af3cbf5d6ca8fe0ca1c2ddebea2d
Reviewed-on: https://go-review.googlesource.com/c/go/+/580283
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Qiqi Huang <huangqiqi@loongson.cn>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>