Crash using compound shapes.

[timluther]

Hi, I've been having trouble with a compound shape collider when using wasm/emscripten, which I believe uses this build of bullet? In short, it crashes here: Uncaught RuntimeError: memory access out of bounds at btCompoundCompoundCollisionAlgorithm::processCollision(btCollisionObjectWrapper const*, btCollisionObjectWrapper const*, btDispatcherInfo const&, btManifoldResult*) (<anonymous>:wasm-function[19723]:0x62f45e) at btCollisionDispatcher::defaultNearCallback(btBroadphasePair&, btCollisionDispatcher&, btDispatcherInfo const&) (<anonymous>:wasm-function[19558]:0x623adf) at btCollisionPairCallback::processOverlap(btBroadphasePair&) (<anonymous>:wasm-function[19576]:0x62420b) at btHashedOverlappingPairCache::processAllOverlappingPairs(btOverlapCallback*, btDispatcher*) (<anonymous>:wasm-function[19542]:0x623535) at btCollisionDispatcher::dispatchAllCollisionPairs(btOverlappingPairCache*, btDispatcherInfo const&, btDispatcher*) (<anonymous>:wasm-function[19567]:0x624105) at btCollisionWorld::performDiscreteCollisionDetection() (<anonymous>:wasm-function[19601]:0x624e43) at btDiscreteDynamicsWorld::internalSingleStepSimulation(float) (<anonymous>:wasm-function[20215]:0x662d90) at btDiscreteDynamicsWorld::stepSimulation(float, int, float) (<anonymous>:wasm-function[20214]:0x662ce4)

on a compound shape object consisting of 8 convex hulls. In order to try and fix this, I've attempted to rebuild ammo.js within emscripten but I could only get so far with that before seeing errors I couldn't solve - I'm not familiar with the build system and I'm got a few time pressures at the moment.

Does any of this look familiar or fixable and have I filed this bug in the right project?