Revert "Fix compilation of the vector tests."

This reverts commit 66f69cfcf076b4fcfb34e6cfc05b480b6e5b6ce9.

We are now using libc++abi's cxxabi.h header which exposes the declarations
that the unit tests expect although they would not seem to comply with the ARM
specification.
Merge pull request #56 from awong-dev/pliard-revert-test-vector-changes

Revert "Fix compilation of the vector tests."