abi-internal: Fix typo in register assignment documentation
abi-internal: Fix typo in register assignment documentation

If register assignment fails, revert back the value to stack

Change-Id: I6f65092461ad4d793206a679a5fef1b560b387f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/384455
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Trust: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Reviewed-by: Austin Clements <7ea35d812706d9213868749011af1ed4fa2f6aa0@google.com>

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