nir/algebraic: Fail build when too many commutative expressions are used

nir/algebraic: Fail build when too many commutative expressions are used

Search patterns that are expected to have too many (e.g., the giant
bitfield_reverse pattern) can be added to a white list.

This would have saved me a few hours debugging. :(

v2: Implement the expected-failure annotation as a property of the
search-replace pattern instead of as a property of the whole list of
patterns.  Suggested by Connor.

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>