FYI: maintainer-check feature

[gccbison]

The 'make maintainer-check' runs the testsuite
using the excellent valgrind software tool.
But 'ltrace -e malloc,free,realloc program -D'
can do similar and then count the number of
malloc/free's. ltrace is less complex then
valgrind and using less memory on itself.
Could be interesting to use ltrace in the
testsuite too in case of valgrind troubles
or to make the testsuite even more reliable.