cmd/internal/obj, cmd/compile: rip off some toolstash bandaids

Change-Id: I402383e893223facae451adbd640113126d5edd9
Reviewed-on: https://go-review.googlesource.com/37873
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/compile/internal/gc/pgen.go

@@ -467,12 +467,6 @@ func gendebug(fnsym *obj.LSym, decls []*Node) {
 
 		fnsym.Autom = append(fnsym.Autom, a)
 	}
-
-	// Reverse to make toolstash happy.
-	// TODO(mdempsky): Remove.
-	for i, j := 0, len(fnsym.Autom)-1; i < j; i, j = i+1, j-1 {
-		fnsym.Autom[i], fnsym.Autom[j] = fnsym.Autom[j], fnsym.Autom[i]
-	}
 }
 
 // fieldtrack adds R_USEFIELD relocations to fnsym to record any

src/cmd/internal/obj/objfile.go

@@ -595,13 +595,7 @@ func gendwarf(ctxt *Link, text []*LSym) []*LSym {
 			})
 		}
 
-		// We want to sort variables by offset, breaking ties
-		// with declaration order. Autom holds variables in
-		// reverse declaration order, so we reverse the
-		// assembled slice and then apply a stable sort.
-		for i, j := 0, len(vars)-1; i < j; i, j = i+1, j-1 {
-			vars[i], vars[j] = vars[j], vars[i]
-		}
+		// Stable sort so that ties are broken with declaration order.
 		sort.Stable(dwarf.VarsByOffset(vars))
 
 		dwarf.PutFunc(dctxt, dsym, s.Name, s.Version == 0, s, s.Size, vars)