unix: use errnoErr in generated wrappers on solaris

To prevent allocations at runtime for common errno values (EAGAIN,
EINVAL, ENOENT).

This was omitted from CL 8190 because the solaris port was broken
otherwise at that time.

Change-Id: I6061d071dddf34d0fd022e0ecfb854b01c56b723
Reviewed-on: https://go-review.googlesource.com/c/sys/+/528375
Reviewed-by: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>

unix/mksyscall_solaris.go

@@ -298,7 +298,7 @@ func main() {
 
 			if doErrno {
 				text += "\tif e1 != 0 {\n"
-				text += "\t\terr = e1\n"
+				text += "\t\terr = errnoErr(e1)\n"
 				text += "\t}\n"
 			}
 			text += "\treturn\n"

unix/zsyscall_illumos_amd64.go

@@ -40,7 +40,7 @@ func readv(fd int, iovs []Iovec) (n int, err error) {
 	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procreadv)), 3, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(len(iovs)), 0, 0, 0)
 	n = int(r0)
 	if e1 != 0 {
-		err = e1
+		err = errnoErr(e1)
 	}
 	return
 }
@@ -55,7 +55,7 @@ func preadv(fd int, iovs []Iovec, off int64) (n int, err error) {
 	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procpreadv)), 4, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(len(iovs)), uintptr(off), 0, 0)
 	n = int(r0)
 	if e1 != 0 {
-		err = e1
+		err = errnoErr(e1)
 	}
 	return
 }
@@ -70,7 +70,7 @@ func writev(fd int, iovs []Iovec) (n int, err error) {
 	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procwritev)), 3, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(len(iovs)), 0, 0, 0)
 	n = int(r0)
 	if e1 != 0 {
-		err = e1
+		err = errnoErr(e1)
 	}
 	return
 }
@@ -85,7 +85,7 @@ func pwritev(fd int, iovs []Iovec, off int64) (n int, err error) {
 	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procpwritev)), 4, uintptr(fd), uintptr(unsafe.Pointer(_p0)), uintptr(len(iovs)), uintptr(off), 0, 0)
 	n = int(r0)
 	if e1 != 0 {
-		err = e1
+		err = errnoErr(e1)
 	}
 	return
 }
@@ -96,7 +96,7 @@ func accept4(s int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (fd int,
 	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procaccept4)), 4, uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)), uintptr(flags), 0, 0)
 	fd = int(r0)
 	if e1 != 0 {
-		err = e1
+		err = errnoErr(e1)
 	}
 	return
 }