tree-optimization/114239 - rework reduction epilogue driving

tree-optimization/114239 - rework reduction epilogue driving

The following reworks vectorizable_live_operation to pass the
live stmt to vect_create_epilog_for_reduction also for early breaks
and a peeled main exit.  This is to be able to figure the scalar
definition to replace.  This reverts the PR114192 fix as it is
subsumed by this cleanup.

	PR tree-optimization/114239
	* tree-vect-loop.cc (vect_get_vect_def): Remove.
	(vect_create_epilog_for_reduction): The passed in stmt_info
	should now be the live stmt that produces the scalar reduction
	result.  Revert PR114192 fix.  Base reduction info off
	info_for_reduction.  Remove special handling of
	early-break/peeled, restore original vector def gathering.
	Make sure to pick the correct exit PHIs.
	(vectorizable_live_operation): Pass in the proper stmt_info
	for early break exits.

	* gcc.dg/vect/vect-early-break_122-pr114239.c: New testcase.