lang: ast: Embedded imports have function scopes too

If we're importing an embedded module, we need to also include any
possible system scope imports (like functions) that might be using the
same namespace. These might be used by a custom CLI frontend to extend
the code with values from the CLI parsing, for example.

lang/ast/structs.go

@@ -3255,6 +3255,18 @@ func (obj *StmtProg) importScope(info *interfaces.ImportData, scope *interfaces.
 			return nil, err
 		}
 
+		// Our embedded scope might also have some functions to add in!
+		systemScope, err := obj.importSystemScope(info.Name)
+		if err != nil {
+			return nil, errwrap.Wrapf(err, "embedded system import of `%s` failed", info.Name)
+		}
+		newScope := scope.Copy()
+		if err := newScope.Merge(systemScope); err != nil { // errors if something was overwritten
+			// XXX: we get a false positive b/c we overwrite the initial scope!
+			// XXX: when we switch to append, this problem will go away...
+			//return nil, errwrap.Wrapf(err, "duplicate scope element(s) in module found")
+		}
+
 		//tree, err := util.FsTree(fs, "/")
 		//if err != nil {
 		//	return nil, err
@@ -3272,7 +3284,7 @@ func (obj *StmtProg) importScope(info *interfaces.ImportData, scope *interfaces.
 		// not try to copy them in from disk or it won't succeed.
 		input.Files = []string{} // clear
 
-		embeddedScope, err := obj.importScopeWithParsedInputs(input, scope, nextVertex)
+		embeddedScope, err := obj.importScopeWithParsedInputs(input, newScope, nextVertex)
 		if err != nil {
 			return nil, errwrap.Wrapf(err, "embedded import of `%s` failed", info.Name)
 		}