This reverts commit 733261c8.

This should avoid cases where scheduling turns a side-exit into a
"useless Icond" which changes the number of exits and is ruled illegal.

This reverts commit d0f23ce9.

(was already included for the benchmark runs for the M2 report)

This reverts commit a0119e59.

Fix applied at wrong place

When code motion past side exits is NOT combined with general register
renaming, the renaming necessary to make it safe to duplicate
instructions may cause final restoration code to be inserted.
Final restoration code is trated specially by its own function.

Before, downward scheduling would sometimes give an unverifiable result
because instructions are duplicated before restoration instructions and
aliasing are applied. If for example a loop increment was moved below
multiple side-exits, the restoration code would still mess up the
correct duplication of the instruction because the aliasing logic for
later side exits would overwrite this change.
As a work-around, this commit ensures that the aliasing logic for
side-exits is applied in-order. This may leave aliasing code that is
utterly useless, which should be cleaned up by DCE.

in debug mode.
Compiling glpk-4.65 exhibited this problem but not when using the
ILP-based instruction scheduling.

time

with regard to scheduling constraints necessitated by code outside of
the superblock. This behavior more closely matches that of the other
dependency calculations giving a more fair comparison.

information.
Correct in the sense that they match the expected scheduling
constraints.