Using basic constant propagation (only integer constants, no arithmetic
calculations), rewrite conditional jump instructions with constant
arguments.
This covers problem description in KT-17007.
Note that it also works transparently with inline functions.
Partial evaluation is required to cover more "advanced" cases.
As a side effect, this also covers KT-3098:
rewrite IF_ICMP<cmp_op>(x, 0) to IF<cmp0_op>(x).