alpha.h: NULL_PTR -> NULL.

alpha.h: NULL_PTR -> NULL.

	* alpha.h: NULL_PTR -> NULL.
	* arm.c: Likewise.
	* arm.h: Likewise.
	* avr.h: Likewise.
	* c4x.c: Likewise.
	* c4x.h: Likewise.
	* i386.c: Likewise.
	* i386.md: Likewise.
	* i860.c: Likewise.
	* ia64.c: Likewise.
	* m68hc11.h: Likewise.
	* rs6000.h: Likewise.
	* sh.c: Likewise.
	* sh.h: Likewise.
	* sparc.h: Likewise.
	* v850.c: Likewise.

	* expr.c: Likewise.
	* final.c: Likewise.
	* gcc.c: Likewise.
	* recog.c: Likewise.

From-SVN: r41831