runtime: cmd/go TestScript/cover_pkgall_runtime broken by CL 388477

[prattmic]

https://go.dev/cl/388477 causes failures in cmd/go TestScript/cover_pkgall_runtime on linux-amd64-longtest.

https://build.golang.org/log/b204a00cd3a2301edb04e903019d3e47aa0c545f

I will be sending revert CLs shortly

cc @bcmills

[gopherbot]

Change https://go.dev/cl/401636 mentions this issue: Revert "syscall: define Syscall in terms of RawSyscall on linux"

[gopherbot]

Change https://go.dev/cl/401634 mentions this issue: Revert "runtime/internal/syscall: use ABIInternal for Syscall6 on amd64"

[gopherbot]

Change https://go.dev/cl/401635 mentions this issue: Revert "syscall: define Syscall6 in terms of RawSyscall6 on linux"

[gopherbot]

Change https://go.dev/cl/401654 mentions this issue: syscall: define Syscall in terms of RawSyscall on linux

[gopherbot]

Change https://go.dev/cl/401656 mentions this issue: runtime/internal/syscall: use ABIInternal for Syscall6 on amd64