Add test for issue 7245

fixes #7245
Add test for issue 7602

fixes #7602
Merge pull request #8284 from skirpichev/7245-7602-tests

Add tests for issues 7245 and 7602
Inequalities: make sure both sides are real when looking at difference

Fixes #8288.  When subtracting lhs - rhs we should be careful they
are real, otherwise could cancel non-real bits.  Add tests.

Also, these should not simplify, add a XFAIL test for that.
Expr: changes to failing tests (insufficient assumptions)