[analyzer] Fix "RhsLoc and LhsLoc bitwidth must be same"

clang: <root>/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp:727:
void assertEqualBitWidths(clang::ento::ProgramStateRef,
  clang::ento::Loc, clang::ento::Loc): Assertion `RhsBitwidth ==
  LhsBitwidth && "RhsLoc and LhsLoc bitwidth must be same!"'

This change adjusts the bitwidth of the smaller operand for an evalBinOp
as a result of a comparison operation. This can occur in the specific
case represented by the test cases for a target with different pointer
sizes.

Reviewed By: NoQ

Differential Revision: https://reviews.llvm.org/D122513