Use mps_root_create_thread in preference to mps_root_create_reg.
New test harness run_test passes pointer to cold end of stack, since this is needed by many tests.
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Change: 195917
* Missing mps_chain_destroy in function/132.
* Need to use platform alignment in the MVFF test cases (function/163, function/164, function/165, function/167, function/170)
* Avoid type pun in function/226.
Update testsets/passing accordingly.
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Change: 182262
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