bug#61489: Increase BLOCK_ALIGN from 1024 to 32768 Originally discovered by Tyler Dodge in his article "Significant Garbage Collection Improvement For Emacs". While testing this change on Archlinux system with Intel i5-7200U CPU, average time of garbage collection gets reduced by ≈25%. Other users report improvements up to 50%. While monitoring PSS of emacs with and without customizations loaded before and after the patch, no statistically significant differences were discovered. So overall, this change is a win. * src/alloc.c (BLOCK_ALIGN): increase from 1024 to 32768.