cmd/go: on AIX, pass -X64 first when invoking ar

    
    Reviewed-on: https://go-review.googlesource.com/111535

From-SVN: r259946

gcc/go/gofrontend/MERGE

-0c9b7a1ca4c6308345ea2a276cf820ff52513592
+6b0355769edd9543e6c5f2270b26b140bb96e9aa
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/cmd/go/internal/work/gccgo.go

@@ -198,7 +198,7 @@ func (gccgoToolchain) pack(b *Builder, a *Action, afile string, ofiles []string)
 			// AIX "ar" command does not know D option.
 			arArgs = append(arArgs, "-X64")
 		}
-		return b.run(a, p.Dir, p.ImportPath, nil, "ar", "rc", arArgs, absAfile, absOfiles)
+		return b.run(a, p.Dir, p.ImportPath, nil, "ar", arArgs, "rc", absAfile, absOfiles)
 	}
 	return nil
 }