[analyzer] refactor makeIntValWithPtrWidth, remove getZeroWithPtrWidth (NFC)

This is a NFC refactoring to change makeIntValWithPtrWidth
and remove getZeroWithPtrWidth to use types when forming values to match
pointer widths. Some targets may have different pointer widths depending
upon address space, so this needs to be comprehended.

Reviewed By: steakhal

Differential Revision: https://reviews.llvm.org/D120134