Add --file-type option to pnacl-dis.
Add --file-type option to pnacl-dis.

With this option, pnacl-dis detects and prints the type of the input file it sees, instead of running disassembly.

BUG=None
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/22353007

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@11931 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client