Remove accidental use of "await" as a name as it becomes a keyword in Py3.7.

Closes #1916.

Cython/Compiler/ExprNodes.py

@@ -2869,16 +2869,16 @@ class WithExitCallNode(ExprNode):
 
     # with_stat   WithStatNode                the surrounding 'with' statement
     # args        TupleNode or ResultStatNode the exception info tuple
-    # await      AwaitExprNode               the await expression of an 'async with' statement
+    # await_expr  AwaitExprNode               the await expression of an 'async with' statement
 
-    subexprs = ['args', 'await']
+    subexprs = ['args', 'await_expr']
     test_if_run = True
-    await = None
+    await_expr = None
 
     def analyse_types(self, env):
         self.args = self.args.analyse_types(env)
-        if self.await:
-            self.await = self.await.analyse_types(env)
+        if self.await_expr:
+            self.await_expr = self.await_expr.analyse_types(env)
         self.type = PyrexTypes.c_bint_type
         self.is_temp = True
         return self
@@ -2905,12 +2905,12 @@ class WithExitCallNode(ExprNode):
         code.putln(code.error_goto_if_null(result_var, self.pos))
         code.put_gotref(result_var)
 
-        if self.await:
+        if self.await_expr:
             # FIXME: result_var temp currently leaks into the closure
-            self.await.generate_evaluation_code(code, source_cname=result_var, decref_source=True)
-            code.putln("%s = %s;" % (result_var, self.await.py_result()))
-            self.await.generate_post_assignment_code(code)
-            self.await.free_temps(code)
+            self.await_expr.generate_evaluation_code(code, source_cname=result_var, decref_source=True)
+            code.putln("%s = %s;" % (result_var, self.await_expr.py_result()))
+            self.await_expr.generate_post_assignment_code(code)
+            self.await_expr.free_temps(code)
 
         if self.result_is_used:
             self.allocate_temp_result(code)

Cython/Compiler/ParseTreeTransforms.py

@@ -1292,7 +1292,7 @@ class WithTransform(CythonTransform, SkipDeclarations):
                                 pos, with_stat=node,
                                 test_if_run=False,
                                 args=excinfo_target,
-                                await=ExprNodes.AwaitExprNode(pos, arg=None) if is_async else None)),
+                                await_expr=ExprNodes.AwaitExprNode(pos, arg=None) if is_async else None)),
                         body=Nodes.ReraiseStatNode(pos),
                     ),
                 ],
@@ -1314,7 +1314,7 @@ class WithTransform(CythonTransform, SkipDeclarations):
                     test_if_run=True,
                     args=ExprNodes.TupleNode(
                         pos, args=[ExprNodes.NoneNode(pos) for _ in range(3)]),
-                    await=ExprNodes.AwaitExprNode(pos, arg=None) if is_async else None)),
+                    await_expr=ExprNodes.AwaitExprNode(pos, arg=None) if is_async else None)),
             handle_error_case=False,
         )
         return node