cmd/link: remove never-set Windows variable

Change-Id: I3d64549b85b71bb63bcc815ce2276af6ca2eb215
Reviewed-on: https://go-review.googlesource.com/29354Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/link/internal/ld/ld.go

@@ -36,6 +36,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
+	"path/filepath"
 	"strconv"
 	"strings"
 )
@@ -58,7 +59,7 @@ func addlib(ctxt *Link, src string, obj string, pathname string) {
 
 	var pname string
 	isshlib := false
-	if (ctxt.Windows == 0 && strings.HasPrefix(name, "/")) || (ctxt.Windows != 0 && len(name) >= 2 && name[1] == ':') {
+	if filepath.IsAbs(name) {
 		pname = name
 	} else {
 		// try dot, -L "libdir", and then goroot.

src/cmd/link/internal/ld/link.go

@@ -176,7 +176,6 @@ type Link struct {
 	Arch      *sys.Arch
 	Debugvlog int
 	Bso       *bufio.Writer
-	Windows   int32
 
 	Loaded bool // set after all inputs have been loaded as symbols