Make prof_tctx accesses atomic.
Make prof_tctx accesses atomic.

Although exceedingly unlikely, it appears that writes to the prof_tctx
field of arena_chunk_map_misc_t could be reordered such that a stale
value could be read during deallocation, with profiler metadata
corruption and invalid pointer dereferences being the most likely
effects.

garoose/jemalloc,lvfeng1130/jemalloc,VRToxin/android_external_jemalloc,ahmetmircik/jemalloc,flyfeifan/jemalloc,Dmitry-Me/jemalloc,AndroidExternal/jemalloc,8l/jemalloc,garoose/jemalloc,Snaipe/jemalloc,glandium/jemalloc,tempbottle/jemalloc,jemalloc/jemalloc-cmake,lilothar/jemalloc,TeamExodus/external_jemalloc,vashstorm/jemalloc,dxq-git/jemalloc,cpeterso/jemalloc,ahmetmircik/jemalloc,CMRemix/android_external_jemalloc,cpeterso/jemalloc,lvfeng1130/jemalloc,leebaok/jemalloc-4.2.1-readcode,AndroidExternal/jemalloc,CMRemix/android_external_jemalloc,lvfeng1130/jemalloc,wfxiang08/jemalloc,Dmitry-Me/jemalloc,wfxiang08/jemalloc,Dmitry-Me/jemalloc,8l/jemalloc,VRToxin/android_external_jemalloc,8l/jemalloc,TeamExodus/external_jemalloc,wespelee/jemalloc,shekkbuilder/jemalloc,ahmetmircik/jemalloc,cpeterso/jemalloc,kmiku7/jemalloc,tempbottle/jemalloc,dxq-git/jemalloc,leebaok/jemalloc-4.2.1-readcode,geekboxzone/mmallow_external_jemalloc,dxq-git/jemalloc,TeamExodus/external_jemalloc,geekboxzone/mmallow_external_jemalloc,lilothar/jemalloc,yy-nm/jemalloc,vashstorm/jemalloc,tempbottle/jemalloc,jemalloc/jemalloc-cmake,wqfish/jemalloc,ahmetmircik/jemalloc,VRToxin/android_external_jemalloc,VRToxin/android_external_jemalloc,wespelee/jemalloc,Snaipe/jemalloc,wqfish/jemalloc,jemalloc/jemalloc-cmake,dxq-git/jemalloc,jemalloc/jemalloc-cmake,flyfeifan/jemalloc,yy-nm/jemalloc,garoose/jemalloc,8l/jemalloc,wespelee/jemalloc,yy-nm/jemalloc,vashstorm/jemalloc,wqfish/jemalloc,wfxiang08/jemalloc,lilothar/jemalloc,cpeterso/jemalloc,AndroidExternal/jemalloc,shekkbuilder/jemalloc,wqfish/jemalloc,wespelee/jemalloc,garoose/jemalloc,awreece/jemalloc,Dmitry-Me/jemalloc,awreece/jemalloc,shekkbuilder/jemalloc,flyfeifan/jemalloc,shekkbuilder/jemalloc,wqfish/jemalloc,glandium/jemalloc,wfxiang08/jemalloc,lilothar/jemalloc,AndroidExternal/jemalloc,glandium/jemalloc,lvfeng1130/jemalloc,vashstorm/jemalloc,awreece/jemalloc,Snaipe/jemalloc,kmiku7/jemalloc,tempbottle/jemalloc,geekboxzone/mmallow_external_jemalloc,glandium/jemalloc,leebaok/jemalloc-4.2.1-readcode,kmiku7/jemalloc,flyfeifan/jemalloc,CMRemix/android_external_jemalloc,awreece/jemalloc,CMRemix/android_external_jemalloc,yy-nm/jemalloc,geekboxzone/mmallow_external_jemalloc,Snaipe/jemalloc,leebaok/jemalloc-4.2.1-readcode,kmiku7/jemalloc,TeamExodus/external_jemalloc