Update S to use StackEntry structures

[ms609]

Retire CT_PUSH and CT_POP

[github-actions]

Performance benchmark results

Call	Status	Change	Time (ms)
as.Splits(bigTrees)	⚪ NSD	-0.03%	24.3 → 23.1, 24.3
as.Splits(someTrees)	⚪ NSD	-1.22%	11.1 → 11.3, 11.1
Consensus(forest1k.888, check = FALSE)	⚪ NSD	2.12%	97 → 95.4, 94.6
Consensus(forest201.80, check = FALSE)	⚪ NSD	1.37%	4.08 → 4.01, 4.04
Consensus(forest21.260, 0.5, FALSE)	⚪ NSD	1.82%	1.25 → 1.22, 1.22
Consensus(forest21.260)	⚪ NSD	1.27%	1.23 → 1.21, 1.22
Consensus(forestMaj, 0.5, FALSE)	⚪ NSD	1.22%	2.97 → 2.94, 2.93
DropTip(tr2000, 5)	⚪ NSD	-0.17%	20.2 → 20.4, 20
DropTip(tr80, 5)	⚪ NSD	0%	0.104 → 0.103, 0.105
DropTip(unlen2k, 5)	⚪ NSD	-3.34%	0.21 → 0.217, 0.216
DropTip(unlen80, 5)	⚪ NSD	-0.77%	0.0402 → 0.0402, 0.0408
lapply(bigSplits, as.phylo)	⚪ NSD	-0.63%	30.4 → 30.5, 30.6
lapply(someSplits, as.phylo)	⚪ NSD	-1.69%	14.2 → 14.5, 14.2
PathLengths(tr2000, full = TRUE)	⚪ NSD	1.2%	19.9 → 19.6, 19.8
PathLengths(tr80, full = TRUE)	🟢 Faster!	72.34%	0.104 → 0.104, 0.0284
PathLengths(tr80Unif, full = TRUE)	🟢 Faster!	71.05%	0.107 → 0.105, 0.0304
RootTree(tr2000, 5)	⚪ NSD	2.69%	0.393 → 0.391, 0.372
RootTree(tr80, c("t3", "t36"))	⚪ NSD	1.17%	0.0703 → 0.0695, 0.0694
RootTree(tr80, "t3")	⚪ NSD	1.08%	0.05 → 0.0499, 0.0488
RootTree(tr80, "t30")	⚪ NSD	0.88%	0.0502 → 0.0503, 0.0489
RootTree(unlen2k, 5)	⚪ NSD	0.1%	0.33 → 0.326, 0.332
RootTree(unlen80, c("t3", "t36"))	⚪ NSD	2.23%	0.0651 → 0.0634, 0.0638
RootTree(unlen80, "t3")	⚪ NSD	0.35%	0.0431 → 0.0429, 0.043
RootTree(unlen80, "t30")	⚪ NSD	0.96%	0.0438 → 0.0434, 0.0433
TreeDist::RobinsonFoulds(forest201.80)	⚪ NSD	-2.17%	15.2 → 15.4, 15.7
TreeDist::RobinsonFoulds(forest21.888)	⚪ NSD	-1.11%	3.24 → 3.19, 3.29
TreeTools:::path_lengths(tr80$edge, tr80$edge.length, FALSE)	⚪ NSD	0.16%	0.0919 → 0.0916, 0.0918
TreeTools:::postorder_order(bal40)	⚪ NSD	0%	0.00162 → 0.00163, 0.00162
TreeTools:::postorder_order(bal40k)	⚪ NSD	0.15%	0.443 → 0.443, 0.442
TreeTools:::postorder_order(dbal40)	⚪ NSD	-0.59%	0.0017 → 0.00169, 0.00172
TreeTools:::postorder_order(dbal40k)	⚪ NSD	0.35%	2.14 → 2.13, 2.14
TreeTools:::postorder_order(dpec40)	⚪ NSD	-1.61%	0.00249 → 0.00253, 0.00254
TreeTools:::postorder_order(dpec40k)	🟣 ~same	3.31%	3430 → 3300, 3390
TreeTools:::postorder_order(drnd80)	⚪ NSD	-0.78%	0.00399 → 0.00401, 0.00404
TreeTools:::postorder_order(nbal40)	⚪ NSD	-0.5%	0.00204 → 0.00204, 0.00206
TreeTools:::postorder_order(nbal40k)	⚪ NSD	-0.24%	2.18 → 2.17, 2.21
TreeTools:::postorder_order(npec40)	⚪ NSD	-1.07%	0.0028 → 0.00283, 0.00282
TreeTools:::postorder_order(npec40k)	🟣 ~same	2.58%	3450 → 3330, 3410
TreeTools:::postorder_order(nrnd80)	⚪ NSD	-1.35%	0.00451 → 0.00457, 0.00457
TreeTools:::postorder_order(pec40)	⚪ NSD	-1.9%	0.00163 → 0.00163, 0.00168
TreeTools:::postorder_order(pec40k)	⚪ NSD	0.17%	0.429 → 0.432, 0.426
TreeTools:::postorder_order(rnd80)	⚪ NSD	-0.53%	0.00208 → 0.0021, 0.00209