Add a step for PIC mode testing to the pnacl toolchain testers.
Add a step for PIC mode testing to the pnacl toolchain testers.

We currently only tests PIC mode for ARM on the toolchain build bot.
This test can be deleted (speeding up that bots) once this CL is committed.

BUG= http://code.google.com/p/nativeclient/issues/detail?id=2760
TEST= manual
Review URL: https://chromiumcodereview.appspot.com/10353015

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@8488 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,sbc100/native_client