Find dwarf.h in libdwarf subdirectory
Summary:
libdwarf headers moved from `/usr/include` to `/usr/include/libdwarf` in [dwarfutils
20160613-2](http://metadata.ftp-master.debian.org/changelogs/main/d/dwarfutils/unstable_changelog).
Adds a check for the library as well, and fixes a tiny typo in the `libunwind` check.
No longer checks for `libdwarf.h`; only `dwarf.h` is used.
Closes https://github.com/facebook/folly/pull/480
Reviewed By: yfeldblum
Differential Revision:
D3878961
Pulled By: Orvid
fbshipit-source-id:
7970d33511bf6d351cec2c8077cb07b85f2f8d33
projects / folly.git / commit