Valgrind-clean mode/clean-up function

[jedbrown]

It'd be useful to have a way to clean up so users can avoid these leaks. PETSc would call it in PetscFinalize so users wouldn't have valgrind noise from BLIS.

$ valgrind --leak-check=full ./obj/haswell/blastest/dblat3.x < blastest/input/dblat3.in                                                                      
==185692== Memcheck, a memory error detector                                                                                                                                                   
==185692== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.                                                                                                                     
==185692== Using Valgrind-3.16.1 and LibVEX; rerun with -h for copyright info                                                                                                                  
==185692== Command: ./obj/haswell/blastest/dblat3.x                                                                                                                                            
==185692==                                                                                                                                                                                     
==185692==                                                                                                                                                                                     
==185692== HEAP SUMMARY:                                                                                                                                                                       
==185692==     in use at exit: 17,824,704 bytes in 41 blocks                                                                                                                                   
==185692==   total heap usage: 92 allocs, 51 frees, 17,836,911 bytes allocated                                                                                                                 
==185692==                                                                                                                                                                                     
==185692== 104 bytes in 1 blocks are possibly lost in loss record 7 of 41                                                                                                                      
==185692==    at 0x483977F: malloc (vg_replace_malloc.c:307)                                                                                                                                   
==185692==    by 0x12E772: bli_fmalloc_align (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                             
==185692==    by 0x29ABD1: bli_pool_init (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                                 
==185692==    by 0x2957B7: bli_apool_array_elem (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                          
==185692==    by 0x12EDD8: bli_sba_rntm_set_pool (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                         
==185692==    by 0x2A0B1D: bli_l3_sup_thread_decorator (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                   
==185692==    by 0x27A643: bli_gemmsup_ref (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                               
==185692==    by 0x12DC67: bli_gemmsup (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                                   
==185692==    by 0x12D3C1: bli_gemm_ex (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                                   
==185692==    by 0x1259B1: dgemm_ (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                                        
==185692==    by 0x112573: dchk1_ (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)                                                                                                        
==185692==    by 0x10F0BE: main (in /home/jed/src/blis/obj/haswell/blastest/dblat3.x)             
[...]

[loveshack]

There is a bli_finalize: https://github.com/flame/blis/blob/master/docs/BLISTypedAPI.md#initialization-and-cleanup

Somewhat related, it might be a good idea to add the "malloc" GCC (and clang?) attribute to malloc-like functions.