Forward-port from gcc-4_6-branch r181936 2011-12-02.

Forward-port from gcc-4_6-branch r181936 2011-12-02.

libgcc/
	Forward-port from gcc-4_6-branch r181936 2011-12-02.

	PR target/51345
	PR target/51002
	* config/avr/lib1funcs.S (__prologue_saves__,
	__epilogue_restores__, __divdi3_moddi3): Enclose parts using
	__SP_H__ in !defined (__AVR_HAVE_8BIT_SP__).  Add FIXME comments.

gcc/
	Forward-port from gcc-4_6-branch r181936 2011-12-02.

	PR target/51002
	* config/avr/avr.md (movhi_sp_r): Set insn condition to
	!AVR_HAVE_8BIT_SP.
	* config/avr/avr.c (output_movhi): Use "clr%B0" instead of "in
	%B0,__SP_H__" if AVR_HAVE_8BIT_SP.
	(avr_file_start): Only print "__SP_H__ = 0x3e" if !AVR_HAVE_8BIT_SP.

From-SVN: r182052