Rangers on entry cache propagation already evaluates equivalences when 
calculating values. This patch also allows it to work with partial 
equivalences, and if the bit sizes are compatible, make use of those 
ranges as well.

It attempts to be conservative, so should be safe.

This resolves regressions in both PR 102540 and PR 102872.

Bootstrapped on x86_64-pc-linux-gnu with no regressions.  Pushed

Andrew