code review 4813052: 5g, 6g, 8g: shift, opt fixes

src/cmd/6g/gsubr.c

 // Derived from Inferno utils/6c/txt.c
 // http://code.google.com/p/inferno-os/source/browse/utils/6c/txt.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 455 matching lines @@
                 n->class = PPARAM;
                 break;
 
         case 2:         // offset output arg
 fatal("shouldnt be used");
                 n->op = OINDREG;
                 n->val.u.reg = D_SP;
                 n->xoffset += types[tptr]->width;
                 break;
         }
+        n->typecheck = 1;
         return n;
 }
 
 /*
  * generate
  *      as $c, reg
  */
 void
 gconreg(int as, vlong c, int reg)
 {
@@ skipping 493 matching lines @@
                 naddr(f, &af, 1);
         if(t != N)
                 naddr(t, &at, 1);
         p = prog(as);
         if(f != N)
                 p->from = af;
         if(t != N)
                 p->to = at;
         if(debug['g'])
                 print("%P\n", p);
-
 
         w = 0;
         switch(as) {
         case AMOVB:
                 w = 1;
                 break;
         case AMOVW:
                 w = 2;
                 break;
         case AMOVL:
@@ skipping 1150 matching lines @@
         naddr(&n2, a, 1);
         goto yes;
 
 yes:
         return 1;
 
 no:
         sudoclean();
         return 0;
 }