Remove XOR swap from Reverse().
Remove XOR swap from Reverse().

gcc 4.8 on x86_64 produces better code for the naive approach than it
does for the XOR swap trick.

chrisdew/node-buffertools,chrisdew/node-buffertools,chrisdew/node-buffertools,bnoordhuis/node-buffertools,bnoordhuis/node-buffertools,bnoordhuis/node-buffertools,chrisdew/node-buffertools,bnoordhuis/node-buffertools