This expands checking for more expressions. This will check underflow
and loss of precision when using call expressions like:
void foo(unsigned);
int i = -1;
foo(i);
This also includes other expressions as well, so it can catch negative
indices to std::vector since it uses unsigned integers for [] and .at()
function.
Patch by: @pfultz2
Differential Revision: https://reviews.llvm.org/D46081
Gabor Marton