Avoid removing elements from the beginning of a vec (#69)

Author: MichaReiser

parser/src/python.lalrpop

@@ -114,11 +114,11 @@ ExpressionStatement: ast::Stmt = {
             let mut targets = vec![set_context(expression, ast::ExprContext::Store)];
             let mut values = suffix;
 
-            while values.len() > 1 {
-                targets.push(set_context(values.remove(0), ast::ExprContext::Store));
-            }
+            let value = Box::new(values.pop().unwrap());
 
-            let value = Box::new(values.into_iter().next().unwrap());
+            for target in values {
+                targets.push(set_context(target, ast::ExprContext::Store));
+            }
 
             ast::Stmt::Assign(
                 ast::StmtAssign { targets, value, type_comment: None, range: (location..end_location).into() }