cmd/compile/internal/gc: cleaning; use range when appropriate

Made use of range statement in for loops.
Cleaning along the way:
-remove unnecessary variable declarations
-rename variables
-remove dead code

This change passes go build -toolexec 'toolstash -cmp' -a std.

Change-Id: Ife8c2a98482a81ba91f5bbb65142d9f3dc46d6ee
Reviewed-on: https://go-review.googlesource.com/14379
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/cmd/compile/internal/gc/util.go b/src/cmd/compile/internal/gc/util.go
index d16cd38009..fc9173e383 100644
--- a/src/cmd/compile/internal/gc/util.go
+++ b/src/cmd/compile/internal/gc/util.go
@@ -36,10 +36,10 @@ func isDigit(c int) bool {
 
 func plan9quote(s string) string {
 	if s == "" {
-		return "'" + strings.Replace(s, "'", "''", -1) + "'"
+		return "''"
 	}
-	for i := 0; i < len(s); i++ {
-		if s[i] <= ' ' || s[i] == '\'' {
+	for _, c := range s {
+		if c <= ' ' || c == '\'' {
 			return "'" + strings.Replace(s, "'", "''", -1) + "'"
 		}
 	}