Decouples guard page use from cache and heap unit size.
Changes the Windows -vmm_block_size to the page size so that there is nothing special about 64K for 4K pages. The logic is that 99% of our usage stays within the VMM reservations these days, so it is not worth the complexity of dealing with 64K sizing for 4K pages.
Removes the guard page adjustments to cache and heap units. Now the specified sizes are the actual usable sizes, with any guard pages added externally and not considered as part of the unit size.
Adjusts the default heap unit sizes down by 8K to maintain the same sizing as before.
Leaves the default cache unit sizes how they were. The sub-64K did not have 8K subtracted and remain small. The 64K will now occupy 72K, but shrinking to 56K is complicated by the quadrupling scheme from 4K to 16K to 64K which previously ended up at 56K.
Issue: #2607 (closed), #4424 (closed) Fixes #2607 (closed)