code review 6086043: cmd/cgo, cmd/go: detect dynamic linker automatically

src/cmd/6c/swt.c

 // Inferno utils/6c/swt.c
 // http://code.google.com/p/inferno-os/source/browse/utils/6c/swt.c
 //
 //      Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
 //      Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
 //      Portions Copyright © 1997-1999 Vita Nuova Limited
 //      Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
 //      Portions Copyright © 2004,2006 Bruce Ellis
 //      Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
 //      Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
@@ skipping 241 matching lines @@
 
                 Bprint(&b, "\n");
                 Bprint(&b, "$$  // exports\n\n");
                 Bprint(&b, "$$  // local types\n\n");
                 Bprint(&b, "$$  // dynimport\n");
                 for(i=0; i<ndynimp; i++)
                         Bprint(&b, "dynimport %s %s %s\n", dynimp[i].local, dynimp[i].remote, dynimp[i].path);
                 Bprint(&b, "\n$$  // dynexport\n");
                 for(i=0; i<ndynexp; i++)
                         Bprint(&b, "dynexport %s %s\n", dynexp[i].local, dynexp[i].remote);
+                Bprint(&b, "\n$$  // dynlinker\n");
+                if(dynlinker != nil) {
+                        Bprint(&b, "dynlinker %s\n", dynlinker);
+                }
                 Bprint(&b, "\n$$\n\n");
         }
         Bprint(&b, "!\n");
 
         outhist(&b);
         for(sym=0; sym<NSYM; sym++) {
                 h[sym].sym = S;
                 h[sym].type = 0;
         }
         sym = 1;
@@ skipping 348 matching lines @@
 }
 
 int32
 maxround(int32 max, int32 v)
 {
         v += SZ_VLONG-1;
         if(v > max)
                 max = xround(v, SZ_VLONG);
         return max;
 }