expanding addrs for initializers

[DJ Delorie]

> 	typedef void * lptr __attribute__((mode(SI)));
> 	long l = (long)(lptr)&l;

(with the TARGET_VALID_POINTER_MODE change)

typedef int *longpointer __attribute__((mode(SI)));
extern void reset();

longpointer j = (longpointer)&reset;

	.file	"dj.c"
	.global	_j
.data
	.type	_j, @object
	.size	_j, 4
_j:
	.short	_reset
	.zero	2
	.ident	"GCC: (GNU) 4.1.0 20050819 (experimental)"