rename BB to Impl and BB* a to Impl* impl
rename aaA to Entry and aaA*[] b to Entry*[] buckets
use core.memory instead of duplicated GC declarations
replace malloc + memset(0) with calloc
Fix logic of pthread type sizes to match C headers.
Merge pull request #513 from ibuclaw/x32arch

Fix logic of pthread type sizes to match C headers.
Merge pull request #510 from dawgfoto/refactorAA

Refactor AA implementation