Patch for LLVM 2.0 release branch

This one needs to go into the 2.0 branch:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070507/049464.html

This is required to fix a bug I introduced that breaks 177.mesa, distray, and cfrac on ARM.

Evan

Done! Thanks Evan.

-Tanya