56fcf0725a
Previously this query depended on the global interning order of Symbols, which meant that irrelevant changes could influence the query and cause recompilations. This commit ensures that the return set is stable and will not be affected by the global order by deterministically (in lexicographic order) choosing a name to use if there are multiple names for a single DefId.
For more information about how rustc works, see the rustc dev guide.