code review 13334052: cmd/gc: eliminate redundant &x.Field nil checks

src/cmd/gc/gen.c

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 /*
  * portable half of code generator.
  * mainly statements and control flow.
  */
 
 #include <u.h>
@@ skipping 611 matching lines @@
 
         // binary
         case OCAP:
         case OCOM:
         case OLEN:
         case OMINUS:
         case ONOT:
         case OPLUS:
                 cgen_discard(nr->left);
                 break;
+········
+        case OIND:
+                cgen_checknil(nr->left);
+                break;
 
         // special enough to just evaluate
         default:
                 tempname(&tmp, nr->type);
                 cgen_as(&tmp, nr);
                 gused(&tmp);
         }
 }
 
 /*
@@ skipping 284 matching lines @@
 Node*
 temp(Type *t)
 {
         Node *n;
 ········
         n = nod(OXXX, N, N);
         tempname(n, t);
         n->sym->def->used = 1;
         return n;
 }