* Makefile.in: Add rules for regrename.o
	* regrename.c: New file.
	* rtl.h (regrename_optimize): Add prototype.
	* toplev.c (rename_registers_dump, flag_rename_registers): New variables
	(compile_file, decode_d_option): Add support for -frename-registers.
	(rest_of_compilation): Call regrename_optimize.
	* config/ia64/ia64.h (HARD_REGNO_RENAME_OK, RENAME_EXTENDED_BLOCKS):
	New macros.

From-SVN: r32916