i#893: Rtl Heap API replacement, part 5: + lock per arena
i#893: Rtl Heap API replacement, part 5:
+ lock per arena

SVN-Revision: 862

LohithBlaze/drmemory,sigma-random/drmemory,code4bones/drmemory,LohithBlaze/drmemory,sigma-random/drmemory,LohithBlaze/drmemory,sigma-random/drmemory,code4bones/drmemory,sigma-random/drmemory,code4bones/drmemory,code4bones/drmemory,LohithBlaze/drmemory,code4bones/drmemory,LohithBlaze/drmemory,sigma-random/drmemory