Add basic Darwin support to libcorkscrew.

This might not seem like much, but it's already better than Mac OS'
backtrace(3).

(cherry picked from commit 2a46f6293f19b9d6100187fbd53088088e671b88)

Change-Id: I197b06c4c19f728ad6f194b2f473bd9dcd99b8a6
Add flush_my_map_info_list() and fix a bug in the Mac load_map_info_list().

(If you fclose(3) rather than pclose(3) a FILE* you got from popen(3),
future popen(3)s fail obscurely, at least on Mac OS.)

(cherry picked from commit 2bf76e143da933184d1392fb9bea3a3896c37e76)

Change-Id: I5578fe06753061b0dbc5ee951ebf31eb2bab0389
Merge changes I5578fe06,I197b06c4

* changes:
  Add flush_my_map_info_list() and fix a bug in the Mac load_map_info_list().
  Add basic Darwin support to libcorkscrew.
Disable darwin build

Change-Id: Ie72bbaab8604cdc14082859b735458a2f73c3074
Merge "Disable darwin build"
Merge branch 'master' of https://android.googlesource.com/platform/system/core into master-tk