Warnings in headers when compiling on OS X

Hi. Certain headers generate warnings like this one:

/usr/local/llvm/include/llvm/Support/IntegersSubset.h:465:12: Implicit conversion loses integer precision: 'uint64_t' (aka 'unsigned long long') to 'unsigned int'

464: static unsigned getNumItemsFromConstant(Constant *C) {
465: return cast<ArrayType>(C->getType())->getNumElements();
466: }

There are a few other conversion warnings in the few headers I'm currently using.

Can I write this up as a bug (i.e., is it fixable)?