Auto merge of #43107 - michaelwoerister:less-span-info-in-debug, r=nikomatsakis

incr.comp.: Don't include span information in the ICH of type definitions

This should improve some of the `regex` tests on perf.rlo. Not including spans into the ICH is harmless until we also cache warnings. To really solve the problem, we need to do more refactoring (see #43088).

r? @nikomatsakis