Fix error positions of undefined builtins and constants (GH-3030)

Currently Cython generates code like this:

     int __Pyx_InitCachedBuiltins(void) {
         __pyx_builtin_NAME = __Pyx_GetBuiltinName(...);
         if (!__pyx_builtin_NAME) __PYX_ERR(1, 44, __pyx_L1_error)
     }

     int __pyx_pymod_exec_MODULE(PyObject *__pyx_pyinit_module) {
         if (__Pyx_InitCachedBuiltins() < 0) __PYX_ERR(1, 1, __pyx_L1_error)
     }

When InitCachedBuiltins and InitCachedConstants call __PYX_ERR, they
pass the file and line where a builtin is used, but then pymod_exec
overwrites it with 1 and 1, and the error message looks like this:

       File "FILE", line 1, in init MODULE.
         import os
     NameError: name 'NAME' is not defined

After this change Cython generates:

     int __pyx_pymod_exec_MODULE(PyObject *__pyx_pyinit_module) {
         if (__Pyx_InitCachedBuiltins() < 0) goto __pyx_L1_error;
     }

and prints:

       File "FILE", line 44, in init MODULE.
         print(NAME)
     NameError: name 'NAME' is not defined

1 files changed, 2 insertions, 2 deletions

diff --git a/Cython/Compiler/ModuleNode.py b/Cython/Compiler/ModuleNode.py
index 2762c2d5b..5c5ad53aa 100644
--- a/Cython/Compiler/ModuleNode.py
+++ b/Cython/Compiler/ModuleNode.py
@@ -2448,10 +2448,10 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
 
         if Options.cache_builtins:
             code.putln("/*--- Builtin init code ---*/")
-            code.put_error_if_neg(self.pos, "__Pyx_InitCachedBuiltins()")
+            code.put_error_if_neg(None, "__Pyx_InitCachedBuiltins()")
 
         code.putln("/*--- Constants init code ---*/")
-        code.put_error_if_neg(self.pos, "__Pyx_InitCachedConstants()")
+        code.put_error_if_neg(None, "__Pyx_InitCachedConstants()")
 
         code.putln("/*--- Global type/function init code ---*/")