[LLVMdev] overflow check

[Pranav Bhandarkar]

>APInt's aren't inherently signed or unsigned; see
>http://llvm.org/doxygen/classllvm_1_1APInt.html#amgrp54923b9793dae891d9489c
c5947f263a

Oh, so that makes sense. I was thrown off by these comments in the APInt.h
*****************************
///It is a functional replacement for common case unsigned integer type like
/// "unsigned", "unsigned long" or "uint64_t", but also allows
non-byte-width
/// integer sizes and large integer value types such as 3-bits, 15-bits, or
more
/// than 64-bits of precision.
*******************************

Pranav