re PR target/61098 (Poor code setting count register for large loops)

re PR target/61098 (Poor code setting count register for large loops)

	PR target/61098
	* config/rs6000/rs6000.c (rs6000_emit_set_const): Remove unneeded
	params and return a bool.  Remove dead code.  Update comment.
	Assert we have a const_int source.  Remove bogus code from
	32-bit HWI days.  Move !TARGET_POWERPC64 handling, and correct
	handling of constants > 2G and reg_equal note, from..
	(rs6000_emit_set_long_const): ..here.  Remove unneeded param and
	return value.  Update comment.  If we can, use a new pseudo
	for intermediate calculations.
	* config/rs6000/rs6000-protos.h (rs6000_emit_set_const): Update
	prototype.
	* config/rs6000/rs6000.md (movsi_internal1_single+1): Update
	call to rs6000_emit_set_const in splitter.
	(movdi_internal64+2, +3): Likewise.

From-SVN: r210932