The Cobalt project has its own Starboard equivalent of libc APIs like
`malloc` and `free`. This CL introduces the wrappers for some libc
functions. In followup CLs, for example occurences of malloc will all
be replaced by base::Malloc in V8.

See b/156155426 for more information.

Bug: v8:10927
Change-Id: Ida3d161a1da56755b681e18b4827e277e6cb4c4d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2416150
Commit-Queue: John Xu <johnx@google.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Auto-Submit: John Xu <johnx@google.com>
Cr-Commit-Position: refs/heads/master@{#70702}