Answer architecture round 10: the paired ruling at fb2c809 is better; a mounted module names its manifest from its files' root, and the mount wrapper returns nothing beside an error

imports_test.go

@@ -38,7 +38,7 @@ func TestPackageImports(t *testing.T) {
 		"data/misc":            nil,
 		"data/sv_SE":           {"data/geo/SE"},
 		"internal/builtinfunc": {"internal/datatype", "internal/drawstate", "internal/grammar", "internal/invariant", "internal/proven"},
-		"internal/datafiles":   {"internal/grammar", "internal/invariant", "internal/jsonvalue"},
+		"internal/datafiles":   {"internal/grammar", "internal/jsonvalue"},
 		"internal/datatype":    nil,
 		"internal/drawstate":   nil,
 		"internal/grammar":     nil,