Rename builtin io to _io

Lib/io.py

@@ -0,0 +1 @@
+from _io import *

vm/src/stdlib/io.rs

@@ -471,7 +471,7 @@ pub fn make_module(vm: &VirtualMachine) -> PyObjectRef {
         "getvalue" => ctx.new_rustfunc(bytes_io_getvalue)
     });
 
-    py_module!(vm, "io", {
+    py_module!(vm, "_io", {
         "open" => ctx.new_rustfunc(io_open),
         "IOBase" => io_base,
         "RawIOBase" => raw_io_base,

vm/src/stdlib/mod.rs

@@ -61,7 +61,7 @@ pub fn get_module_inits() -> HashMap<String, StdlibInitFunc> {
     // disable some modules on WASM
     #[cfg(not(target_arch = "wasm32"))]
     {
-        modules.insert("io".to_string(), Box::new(io::make_module));
+        modules.insert("_io".to_string(), Box::new(io::make_module));
         modules.insert("_os".to_string(), Box::new(os::make_module));
         modules.insert("socket".to_string(), Box::new(socket::make_module));
     }