Tidy some clang 3.3 patches

.. removed 100-gcc462-ptrdiff_t.patch as it was empty
.. regenerated 120-fix-sysroot-paths.patch as it was offset
Fix up clang 3.3 triple stuff more

.. merged 130-prefix-program-names-by-triple.patch and
.. 150-fix_triple_transformation.patch

add Driver::Prefix and calculate that before fudging
i686-* to i386-* then use that when looking for other
programs in ToolChain::GetProgramPath()
Remove .orig added by a clang 3.3 patch