Blender 2.75: Fix compilation error caused by the addons fix

It was relying on a new function introduced by in 958c2087.

source/blender/python/BPY_extern.h

@@ -86,6 +86,7 @@ void	BPY_driver_reset(void);
 float	BPY_driver_exec(struct ChannelDriver *driver, const float evaltime);
 
 int		BPY_button_exec(struct bContext *C, const char *expr, double *value, const bool verbose);
+int		BPY_string_exec_ex(struct bContext *C, const char *expr, bool use_eval);
 int		BPY_string_exec(struct bContext *C, const char *expr);
 
 void	BPY_DECREF(void *pyob_ptr);	/* Py_DECREF() */

source/blender/python/intern/bpy_interface.c

@@ -607,7 +607,7 @@ int BPY_button_exec(bContext *C, const char *expr, double *value, const bool ver
 	return error_ret;
 }
 
-int BPY_string_exec(bContext *C, const char *expr)
+int BPY_string_exec_ex(bContext *C, const char *expr, bool use_eval)
 {
 	PyGILState_STATE gilstate;
 	PyObject *main_mod = NULL;
@@ -630,7 +630,7 @@ int BPY_string_exec(bContext *C, const char *expr)
 	bmain_back = bpy_import_main_get();
 	bpy_import_main_set(CTX_data_main(C));
 
-	retval = PyRun_String(expr, Py_eval_input, py_dict, py_dict);
+	retval = PyRun_String(expr, use_eval ? Py_eval_input : Py_file_input, py_dict, py_dict);
 
 	bpy_import_main_set(bmain_back);
 
@@ -650,6 +650,10 @@ int BPY_string_exec(bContext *C, const char *expr)
 	return error_ret;
 }
 
+int BPY_string_exec(bContext *C, const char *expr)
+{
+	return BPY_string_exec_ex(C, expr, true);
+}
 
 void BPY_modules_load_user(bContext *C)
 {