Fixed xcode build warning in shell.cc (out of order initialization).

Fixed null-pointer dereference in the compiler when running without
SSE3 support (Chromium issue 77654).

Fixed x64 compilation error due to some dead code. (Issue 1286)

Introduced scons target to build the preparser stand-alone example.

Made FreeBSD build and pass all tests.

Review URL: http://codereview.chromium.org/6759025

git-svn-id: http://v8.googlecode.com/svn/trunk@7427 ce2b1a6d-e550-0410-aec6-3dcde31c8c00