MINOR: activity/memprofile: monitor non-portable calls as well

MINOR: activity/memprofile: monitor non-portable calls as well

Some dependencies might very well rely on posix_memalign(), strndup()
or other less portable callsn making us miss them when chasing memory
leaks, resulting in negative global allocation counters. Let's provide
the handlers for the following functions:

  strndup()        // _POSIX_C_SOURCE >= 200809L || glibc >= 2.10
  valloc()         // _BSD_SOURCE || _XOPEN_SOURCE>=500 || glibc >= 2.12
  aligned_alloc()  // _ISOC11_SOURCE
  posix_memalign() // _POSIX_C_SOURCE >= 200112L
  memalign()       // obsolete
  pvalloc()        // obsolete

This time we don't fail if they're not found, we just silently forward
the calls.