avr-protos.h (extra_constraint): Delete.

	* config/avr/avr-protos.h (extra_constraint): Delete.
	(extra_constraint_Q): New declaration.
	* config/avr/constraints.md: New file.
	* config/avr/avr.md: Include it.
	(REG_X, REG_Y, REG_Z, REG_W): New constants.
	(TMP_REGNO, ZERO_REGNO): Likewise.
	(UNSPEC_STRLEN, UNSPEC_INDEX_JMP): Likewise.
	* config/avr/avr.c (avr_reg_class_from_letter): Delete.
	(extra_constraint): Delete.
	(extra_constraint_Q): Test for memory constraint 'Q'.
	* config/avr/avr.h (REG_X,REG_Y,REG_Z,REG_W): Delete.
	(REG_CLASS_FROM_LETTER): Delete.
	(CONST_OK_FOR_LETTER_P): Delete.
	(CONST_DOUBLE_OK_FOR_LETTER_P): Delete.
	(EXTRA_CONSTRAINT): Delete.
	(TMP_REGNO): Delete.
	(ZERO_REGNO): Delete.

From-SVN: r112352