[analyzer] Handle comparison between non-default AS symbol and constant

Summary:
When comparing a symbolic region and a constant, the constant would be
widened or truncated to the width of a void pointer, meaning that the
constant could be incorrectly truncated when handling symbols for
non-default address spaces. In the attached test case this resulted in a
false positive since the constant was truncated to zero. To fix this,
widen/truncate the constant to the width of the symbol expression's
type.

This commit does not consider non-symbolic regions as I'm not sure how
to generalize getting the type there.

This fixes PR40814.

Reviewers: NoQ, zaks.anna, george.karpenkov

Reviewed By: NoQ

Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, jdoerfert, Charusso, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58665

llvm-svn: 355592