early-remat.c: Fix new/delete mismatch [PR100230]

This simple patch fixes a mistmatched operator new/delete in
early-remat.c which triggers ASan errors on (at least) AArch64 when
compiling SVE code.

gcc/ChangeLog:

	PR rtl-optimization/100230
	* early-remat.c (early_remat::sort_candidates): Use delete[]
	instead of delete for array allocated with new[].

gcc/early-remat.c

@@ -1059,7 +1059,7 @@ early_remat::sort_candidates (void)
 
   m_candidates.qsort (compare_candidates);
 
-  delete postorder_index;
+  delete[] postorder_index;
 }
 
 /* Commit to the current candidate indices and initialize cross-references.  */