i#111 64-bit: allow 64-bit GPR registers on fastpath, and for scratch regs ignore r8-r15 for now (until we have i#1632 byte-to-byte and don't need a/b/c/d).
i#111 64-bit: allow 64-bit GPR registers on fastpath, and for scratch regs
ignore r8-r15 for now (until we have i#1632 byte-to-byte and don't need
a/b/c/d).

SVN-Revision: 2082

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