Only enable sandbox extensions on mac.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@169180 268f45cc-cd09-0410-ab3c-d52691b4dbfc
[EFL] Add include path of compact_unwind_encoding.h if FTL JIT is enabled
https://bugs.webkit.org/show_bug.cgi?id=132907

Patch by Zsolt Borbely <zsborbely.u-szeged@partner.samsung.com> on 2014-05-21
Reviewed by Gyuyoung Kim.

.:
* Source/cmake/FindLIBCXXABI.cmake: Added.
* Source/cmake/OptionsEfl.cmake:

Source/JavaScriptCore:
* CMakeLists.txt:

Tools:
We need the mach-o/compact_unwind_encoding.h header from libc++abi-dev package
in JavaScriptCore/ftl/FTLUnwindInfo.cpp when FTL JIT is enabled.

* efl/install-dependencies:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@169181 268f45cc-cd09-0410-ab3c-d52691b4dbfc