Replace SourceRootCrates hashset output with slice for deterministic order

crates/hir/src/symbols.rs

@@ -165,6 +165,7 @@ impl<'a> SymbolCollector<'a> {
         // Record renamed imports.
         // FIXME: In case it imports multiple items under different namespaces we just pick one arbitrarily
         // for now.
+        // FIXME: This parses!
         for id in scope.imports() {
             let source = id.import.child_source(self.db.upcast());
             let Some(use_tree_src) = source.value.get(id.idx) else { continue };