Extended BPFCheckAndAdjustIR pass with sinkMinMax() transformation
that undoes LICM hoistMinMax pass.
The undo transformation converts the following patterns:
x < min(a, b) -> x < a && x < b
x > min(a, b) -> x > a || x > b
x < max(a, b) -> x < a || x < b
x > max(a, b) -> x > a && x > b
Where 'a' or 'b' is a constant.
Also supports `sext min(...) ...` and `zext min(...) ...`.
~~~
This was previously commited as 09feee559a and reverted in
0bf9bfeacc because of the testbot memory leak report:
https://lab.llvm.org/buildbot/#/builders/5/builds/34931
The memory leak issue was caused by incorrect instruction removal
sequence in skinMinMaxBB():
I->dropAllReferences(); --------> I->eraseFromParent();
I->removeFromParent(); fixed to
Differential Revision: https://reviews.llvm.org/D147990
18e13739b8