This modifies the torture test script to actually link and run the
tests in addition to just translating them.

It includes a number of bug fixes as well, particularly in the
handling of boolean values. There is some cleanup of memory address
handling, and in many cases it can avoid generating useless address
computations.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4369
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1890283002 .