[analyzer] Expand conversion check to check more expressions for overflow and underflow

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