Add tracing mmap and munmap functions

[Bojun-Seo]

Current version of heaptrace doesn't trace mmap and munmap functions.
Add tracing these functions to detect memory leak caused by them.

[Bojun-Seo]

@honggyukim
You removed this feature since the implementation was not mature enough.
32163c3
Can you tell me what was not mature? if you remember?

[honggyukim]

As far as I remember, the mmap hooking was removed because the behaviors of mmap heavily depends on input flags so it's not simple enough to handle it.

We may have to handle only specific flags such as MAP_ANON, etc and ignore the rest.