Decrease lmr depth if static eval decreases a lot
This tweak originally had some more conditions which have been simplified away.
Passed STC
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 60064 W: 15797 L: 15439 D: 28828
Ptnml(0-2): 236, 7080, 15106, 7310, 300
https://tests.stockfishchess.org/tests/view/67a2af9cfedef70e42ac3325
Passed LTC
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 76794 W: 19740 L: 19337 D: 37717
Ptnml(0-2): 61, 8327, 21236, 8694, 79
https://tests.stockfishchess.org/tests/view/67a2c904fedef70e42ac374d
Passed Non-Regression VVLTC scaling check
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 29046 W: 7581 L: 7389 D: 14076
Ptnml(0-2): 2, 2557, 9213, 2749, 2
https://tests.stockfishchess.org/tests/view/67a54b591c4a3ea87241cb83
Passed simplification STC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 212448 W: 55244 L: 55217 D: 101987
Ptnml(0-2): 932, 25283, 53707, 25430, 872
https://tests.stockfishchess.org/tests/view/67aaacb02554387b116f698f
Passed simplification LTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 185736 W: 47270 L: 47217 D: 91249
Ptnml(0-2): 141, 20568, 51394, 20627, 138
https://tests.stockfishchess.org/tests/view/67ab8efa133d55b1d3bc1397
closes https://github.com/official-stockfish/Stockfish/pull/5878
Bench: 2512420