libgo patch committed: Pass -X option to ar on AIX

[Ian Lance Taylor]

This libgo patch by Tony Reix passes a -X option to ar on AIX, so that
it does the right object file handling.  Bootstrapped and ran Go
testsuite on x86_64-pc-linux-gnu.  Committed to mainline.

Ian

Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE     (revision 255062)
+++ gcc/go/gofrontend/MERGE     (working copy)
@@ -1,4 +1,4 @@
-1db7dc97d01ee230ff4874ce1c9775a24ffd16ac
+57adb928c3cc61ac8fa47554394670a1c455afc2
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: libgo/go/cmd/go/internal/work/build.go
===================================================================
--- libgo/go/cmd/go/internal/work/build.go      (revision 254090)
+++ libgo/go/cmd/go/internal/work/build.go      (working copy)
@@ -2757,7 +2757,14 @@ func (gccgoToolchain) pack(b *Builder, p
        absAfile := mkAbs(objDir, afile)
        // Try with D modifier first, then without if that fails.
        if b.run(p.Dir, p.ImportPath, nil, "ar", "rcD", absAfile, absOfiles) != 
nil {
-               return b.run(p.Dir, p.ImportPath, nil, "ar", "rc", absAfile, 
absOfiles)
+               if cfg.Goos == "aix" && cfg.Goarch == "ppc64" {
+                       // AIX puts both 32-bit and 64-bit objects in the same 
archive.
+                       // Tell the AIX "ar" command to only care about 64-bit 
objects.
+                       // AIX "ar" command does not know D option.
+                       return b.run(p.Dir, p.ImportPath, nil, "ar", "-X64", 
"rc", absAfile, absOfiles)
+               } else {
+                       return b.run(p.Dir, p.ImportPath, nil, "ar", "rc", 
absAfile, absOfiles)
+               }
        }
        return nil
 }
Index: libgo/go/go/internal/gccgoimporter/importer.go
===================================================================
--- libgo/go/go/internal/gccgoimporter/importer.go      (revision 254090)
+++ libgo/go/go/internal/gccgoimporter/importer.go      (working copy)
@@ -104,12 +104,14 @@ func openExportFile(fpath string) (reade
                // TODO(pcc): Read the archive directly instead of using "ar".
                f.Close()
                closer = nil
+               var cmd *exec.Cmd
 
-               cmd := exec.Command("ar", "p", fpath)
                if runtime.GOOS == "aix" && runtime.GOARCH == "ppc64" {
                        // AIX puts both 32-bit and 64-bit objects in the same 
archive.
                        // Tell the AIX "ar" command to only care about 64-bit 
objects.
-                       cmd.Env = append(os.Environ(), "OBJECT_MODE=64")
+                       cmd = exec.Command("ar", "-X64", "p", fpath)
+               } else {
+                       cmd = exec.Command("ar", "p", fpath)
                }
                var out []byte
                out, err = cmd.Output()