Auto merge of #56264 - petrochenkov:typonly, r=nikomatsakis

resolve: Extern prelude is for type namespace only

Fixes https://github.com/rust-lang/rust/issues/56263 (stable-to-beta regression)

src/test/ui/imports/issue-56263.rs

@@ -0,0 +1,8 @@
+// compile-pass
+// edition:2018
+
+use ::std;
+
+fn main() {
+    let std = 10;
+}