improve syscall callstacks for sysenter
improve syscall callstacks for sysenter

SVN-Revision: 347

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