64-bit fixes.
 [jmk] --rw-rw-r-- M 107020 glenda sys 4248 Nov 19 20:50 sys/src/cmd/2c/enam.c
	/n/sourcesdump/2005/1119/plan9/sys/src/cmd/2c/enam.c:421,424 - 
	/n/sourcesdump/2005/1120/plan9/sys/src/cmd/2c/enam.c:421,425
	  	"UNPK",
	  	"WORD",
	  	"SIGNAME",
	+ 	"LAST",
	  };
 [jmk] --rw-rw-r-- M 107020 glenda sys 6241 Nov 19 20:50 sys/src/cmd/2c/gc.h
	/n/sourcesdump/2005/1119/plan9/sys/src/cmd/2c/gc.h:335,340 - 
	/n/sourcesdump/2005/1120/plan9/sys/src/cmd/2c/gc.h:335,341
	  void	fpbranch(void);
	  void	patch(Prog*, long);
	  void	gpseudo(int, Sym*, int, long);
	+ void	gpseudotree(int, Sym*, Node*);
	  
	  void	indx(Node*);
	  void	bcomplex(Node*);
 [jmk] --rw-rw-r-- M 107020 glenda sys 17160 Nov 19 20:50 sys/src/cmd/2c/swt.c
	/n/sourcesdump/2005/1119/plan9/sys/src/cmd/2c/swt.c:964,970 - 
	/n/sourcesdump/2005/1120/plan9/sys/src/cmd/2c/swt.c:964,970
	  		p->from.displace = 4;
	  		return;
	  	}
	- 	gpseudo(ADATA, s, D_TREE, (long)a);
	+ 	gpseudotree(ADATA, s, a);
	  	p->from.offset += o;
	  	p->from.displace = w;
	  }
 [jmk] --rw-rw-r-- M 107020 glenda sys 17847 Nov 19 20:50 sys/src/cmd/2c/txt.c
	/n/sourcesdump/2005/1119/plan9/sys/src/cmd/2c/txt.c:674,683 - 
	/n/sourcesdump/2005/1120/plan9/sys/src/cmd/2c/txt.c:674,683
	  	} else {
	  		p->from.type = gf;
	  		if(gf == D_CONST) {
	- 			p->from.offset = (long)f;
	+ 			p->from.offset = (long)(uintptr)f;
	  			if(typefd[i]) {
	  				p->from.type = D_FCONST;
	- 				p->from.dval = (long)f;
	+ 				p->from.dval = (long)(uintptr)f;
	  			}
	  		}
	  	}
	/n/sourcesdump/2005/1119/plan9/sys/src/cmd/2c/txt.c:687,693 - 
	/n/sourcesdump/2005/1120/plan9/sys/src/cmd/2c/txt.c:687,693
	  	} else {
	  		p->to.type = gt;
	  		if(gt == D_CONST)
	- 			p->to.offset = (long)t;
	+ 			p->to.offset = (long)(uintptr)t;
	  	}
	  	if(o == OBIT) {
	  		p->from.field = f->type->nbits;
	/n/sourcesdump/2005/1119/plan9/sys/src/cmd/2c/txt.c:839,849 - 
	/n/sourcesdump/2005/1120/plan9/sys/src/cmd/2c/txt.c:839,862
	  	if(a == ADATA)
	  		pc--;
	  	p->as = a;
	- 	if(g != D_TREE) {
	- 		p->to.type = g;
	- 		p->to.offset = v;
	- 	} else
	- 		naddr((Node*)v, &p->to, D_NONE);
	+ 	if(g == D_TREE)
	+ 		abort();	/* obsolete */
	+ 	p->to.type = g;
	+ 	p->to.offset = v;
	+ 	p->from.sym = s;
	+ 	p->from.type = D_EXTERN;
	+ 	if(s->class == CSTATIC)
	+ 		p->from.type = D_STATIC;
	+ }
	+ 
	+ void
	+ gpseudotree(int a, Sym *s, Node *n)
	+ {
	+ 	nextpc();
	+ 	if(a == ADATA)
	+ 		pc--;
	+ 	p->as = a;
	+ 	naddr(n, &p->to, D_NONE);
	  	p->from.sym = s;
	  	p->from.type = D_EXTERN;
	  	if(s->class == CSTATIC)