runtime: use 64 bits of hash seed on arm64

This is the same issue as #33960, but on gofrontend.

Change-Id: I949c2283cd2c26acece6b2ce79f3a5a26bddfd4a
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/220297
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
1 file changed