HiPE's range analysis would not update the arguments of a callee when
the result of the call was ignored.

Fixes ERL-278.

Two tests are added, primarily aimed at the range splitters.

 * test_float_spills, which exercises the rare case of high floating
   point register pressure, including spill slot move coalescing.
 * test_infinite_loops, which tests that various infinite loops are
   properly compiled and do contain reduction tests (otherwise they
   would permanently hog their scheduler and not notice being sent an
   exit signal).

 * Omit bounds check in more cases.
   A test case that needs this change to omit bounds check is added.
 * Improve code generation by reformulating bounds check to decrease
   register pressure.

It was assumed in hipe_icode_fp:filter_map/3 that either all
predecessors would have an up-to-date ("assigned") tagged copy, or none
of them.

This is temporarily false during the fixpoint loop in
basic_floats:test_icode_type_crash_2/0, which exercises the
all_args_equal(Bindings) =:= true branch, that would previously
erroneously end up in the 'false' branch, which is what caused the crash
in that case.

This is likewise only temporarily false during the fixpoint loop in
basic_floats:test_icode_type_crash/0, but that case instead exercises
the 'false' branch, justifying the inclusion of both tests.