tree-optimization/99024 - fix leak in loop vect analysis

tree-optimization/99024 - fix leak in loop vect analysis

When we analyzed a loop as epilogue but later in peeling decide
we're not going to use it then in the DTOR we clear the original
loops ->aux which causes us to leak the main loop vinfo.

Fixed by only clearing aux if it is associated with the vinfo
we're destroying.

2021-02-10  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/99024
	* tree-vect-loop.c (_loop_vec_info::~_loop_vec_info): Only
	clear loop->aux if it is associated with the destroyed loop_vinfo.