runtime: save some stack space for racecall on ARM64
runtime: save some stack space for racecall on ARM64

To avoid nosplit overflow in -race -N -l build.

For #51247.

Change-Id: I48426bbd4adefd18eaf26ed51b4113c6a28305b8
Reviewed-on: https://go-review.googlesource.com/c/go/+/386716
Trust: Cherry Mui <d62e63aa42ce272d7b6a5055d97e942b33a34679@google.com>
Run-TryBot: Cherry Mui <d62e63aa42ce272d7b6a5055d97e942b33a34679@google.com>
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Michael Knyszek <4473450dc5c88f06e1fb787f303d7805ec2aee65@google.com>

CAFxX/go,CAFxX/go,nawawi/go,CAFxX/go,cloudflare/go,golang/go,golang/go,nawawi/go,CAFxX/go,cloudflare/go,CAFxX/go,nawawi/go,cloudflare/go,golang/go,golang/go,cloudflare/go,CAFxX/go,nawawi/go,cloudflare/go,CAFxX/go,nawawi/go,nawawi/go,nawawi/go,golang/go,golang/go,cloudflare/go,golang/go,cloudflare/go,nawawi/go,CAFxX/go,golang/go,cloudflare/go