code review 4406042: build: use gcc -Werror

src/cmd/5c/peep.c

 // Inferno utils/5c/peep.c
 // http://code.google.com/p/inferno-os/source/browse/utils/5c/peep.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 1082 matching lines @@
                 if(v->reg == REGRET)
                         return 2;
                 if(v->type == D_FREG)
                 if(v->reg == FREGRET)
                         return 2;
 
         case ABL:       /* funny */
                 if(v->type == D_REG) {
                         if(v->reg <= REGEXT && v->reg > exregoffset)
                                 return 2;
-                        if(v->reg == REGARG)
+                        if(v->reg == (uchar)REGARG)
                                 return 2;
                 }
                 if(v->type == D_FREG)
                         if(v->reg <= FREGEXT && v->reg > exfregoffset)
                                 return 2;
 
                 if(s != A) {
                         if(copysub(&p->to, v, s, 1))
                                 return 1;
                         return 0;
                 }
                 if(copyau(&p->to, v))
                         return 4;
                 return 3;
 
         case ATEXT:     /* funny */
                 if(v->type == D_REG)
-                        if(v->reg == REGARG)
+                        if(v->reg == (uchar)REGARG)
                                 return 3;
                 return 0;
         }
         return 0;
 }
 
 int
 a2type(Prog *p)
 {
 
@@ skipping 328 matching lines @@
                                 continue;
                         }
                         if(t1 == End || t1 == Branch) {
                                 applypred(r, &j1, Falsecond, Keepbranch);
                                 excise(r);
                                 continue;
                         }
                 }
         }
 }