* alpha/linux.h: Define __gnu_linux__ wherever __linux__ is
	defined, and __gnu_hurd__ wherever __GNU__ is defined.
	* arm/linux-elf.h: Likewise.
	* cris/aout.h: Likewise.
	* cris/linux.h: Likewise.
	* i370/linux.h: Likewise.
	* i386/gnu.h: Likewise.
	* i386/linux-aout.h: Likewise.
	* i386/linux-oldld.h: Likewise.
	* i386/linux.h: Likewise.
	* i386/linux64.h: Likewise.
	* ia64/linux.h: Likewise.
	* m68k/linux-aout.h: Likewise.
	* m68k/linux.h: Likewise.
	* mips/linux.h: Likewise.
	* pa/pa-linux.h: Likewise.
	* pj/linux.h: Likewise.
	* rs6000/sysv4.h: Likewise.
	* s390/linux.h: Likewise.
	* sh/linux.h: Likewise.
	* sparc/linux-aout.h: Likewise.
	* sparc/linux.h: Likewise.
	* sparc/linux64.h: Likewise.
	* xtensa/linux.h: Likewise.

From-SVN: r52279