Revert "0.8 support: use 'instanceof' instead of '__proto__' test"
Revert "0.8 support: use 'instanceof' instead of '__proto__' test"

This reverts commit 967262f6c43a7c94828f40dbd4ee58759f2bb4d9.

isaacs/node-graceful-fs,isaacs/node-graceful-fs,etiktin/node-graceful-fs