Enable tracing of memory/pthread functions

This is _slow_ but manageable.

There is no backtracing for these symbols, and most do not include timing
information either.

malloc, realloc, and calloc are timed so that we can potentially infer whether
or not a syscall was made.

Signed-off-by: Jeremy C. Andrus <jeremya@cs.columbia.edu>
remove cruft in java_backtrace files

Signed-off-by: Jeremy C. Andrus <jeremya@cs.columbia.edu>