syscall: enable TestSyscallNoError on all Linux 32-bit architectures
syscall: enable TestSyscallNoError on all Linux 32-bit architectures

Check the size of uintptr instead of listing GOARCHes explicitly. This
will make the test also run on linux/mips{,le}.

Change-Id: I649f15d293002afc1360b1913910202c3e5188b7
Reviewed-on: https://go-review.googlesource.com/135715
Run-TryBot: Tobias Klauser <0a68dd4915066ec5d3f81f75a828fee53dcc8822@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/go,josharian/go,josharian/go,golang/go,CAFxX/go,golang/go,cloudflare/go,nawawi/go,CAFxX/go,akutz/go,akutz/go,akutz/go,nawawi/go,CAFxX/go,CAFxX/go,CAFxX/go,nawawi/go,golang/go,golang/go,CAFxX/go,josharian/go,akutz/go,nawawi/go,cloudflare/go,cloudflare/go,akutz/go,golang/go,nawawi/go,josharian/go,josharian/go,akutz/go,golang/go,josharian/go,nawawi/go,akutz/go,cloudflare/go,cloudflare/go,nawawi/go,josharian/go,golang/go,CAFxX/go,cloudflare/go,cloudflare/go,CAFxX/go,josharian/go,nawawi/go,akutz/go,cloudflare/go