cmd/link/internal/ld: removed some uses of stringsCompare

Only one use of stringsCompare is left. Cannot simply be replaced by
strings.Compare for bootstrapping reasons I guess.
Moving the function away from util.go to the actual destination data.go
also would not help much. So I left this one unchanged for readability and convenience.

Change-Id: I60d22fec0be8f8c47c80586436f9a550af59194e
Reviewed-on: https://go-review.googlesource.com/14953Reviewed-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/macho.go

@@ -625,10 +625,10 @@ func (x machoscmp) Less(i, j int) bool {
 	k1 := symkind(s1)
 	k2 := symkind(s2)
 	if k1 != k2 {
-		return k1-k2 < 0
+		return k1 < k2
 	}
 
-	return stringsCompare(s1.Extname, s2.Extname) < 0
+	return s1.Extname < s2.Extname
 }
 
 func machogenasmsym(put func(*LSym, string, int, int64, int64, int, *LSym)) {

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

@@ -684,21 +684,11 @@ func addimports(datsect *IMAGE_SECTION_HEADER) {
 	Cseek(endoff)
 }
 
-type pescmp []*LSym
+type byExtname []*LSym
 
-func (x pescmp) Len() int {
-	return len(x)
-}
-
-func (x pescmp) Swap(i, j int) {
-	x[i], x[j] = x[j], x[i]
-}
-
-func (x pescmp) Less(i, j int) bool {
-	s1 := x[i]
-	s2 := x[j]
-	return stringsCompare(s1.Extname, s2.Extname) < 0
-}
+func (s byExtname) Len() int           { return len(s) }
+func (s byExtname) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s byExtname) Less(i, j int) bool { return s[i].Extname < s[j].Extname }
 
 func initdynexport() {
 	nexport = 0
@@ -715,7 +705,7 @@ func initdynexport() {
 		nexport++
 	}
 
-	sort.Sort(pescmp(dexport[:nexport]))
+	sort.Sort(byExtname(dexport[:nexport]))
 }
 
 func addexports() {