Don't try to define the same label twice, as that produces a

label redefinition error.

R=gri
DELTA=6  (0 added, 0 deleted, 6 changed)
OCL=26357
CL=26372

test/bugs/bug140.go

@@ -7,12 +7,12 @@
 package main
 
 func main() {
-	if {} else L: ;
-	if {} else L: main() ;
+	if {} else L1: ;
+	if {} else L2: main() ;
 }
 
 /*
 These should be legal according to the spec.
-bug140.go:6: syntax error near L
-bug140.go:7: syntax error near L
+bug140.go:6: syntax error near L1
+bug140.go:7: syntax error near L2
 */

test/golden.out

@@ -137,8 +137,8 @@ bugs/bug139.go:7: fatal error: naddr: ONAME class x 5
 BUG should compile
 
 =========== bugs/bug140.go
-bugs/bug140.go:6: syntax error near L
-bugs/bug140.go:7: syntax error near L
+bugs/bug140.go:6: syntax error near L1
+bugs/bug140.go:7: syntax error near L2
 BUG should compile
 
 =========== fixedbugs/bug016.go