function abs doesn't support 64bit integer, so i add a fuction

I add a function abs64 to support abs for 64 bit integer

llvmabsfault.patch (800 Bytes)

We already have a abs64 function in MathExtras.h so there's no need to reimplement it.
I've applied your change with here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090803/083984.html

I add a function abs64 to support abs for 64 bit integer

There already is one in MathExtras.h

llvmabsfault.patch (800 Bytes)