syscall: simplify execve handling on libc platforms
Rather than providing three different execve variables for different
platforms, use a single variable. Provide a small wrapper that handles
conversion to uintptr for the AIX/Solaris case.
Note that this removes special handling for openbsd/mips64, which is
now a dead port.
Updates #61546
Change-Id: I3d6387c31669f64bfb61639536803e595f478647
Reviewed-on: https://go-review.googlesource.com/c/go/+/693880 Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Carlos Amedee <carlos@golang.org>