Add a UI test for types named the same as primitives

tests/ui/resolve/conflicting-primitive-names.rs

@@ -0,0 +1,30 @@
+//@ check-pass
+#![allow(non_camel_case_types)]
+#![allow(unused)]
+
+// Ensure that primitives do not interfere with user types of similar names
+
+macro_rules! make_ty_mod {
+    ($modname:ident, $ty:tt) => {
+        mod $modname {
+            struct $ty {
+                a: i32,
+            }
+
+            fn assignment() {
+                let $ty = ();
+            }
+
+            fn access(a: $ty) -> i32 {
+                a.a
+            }
+        }
+    };
+}
+
+make_ty_mod!(check_f16, f16);
+make_ty_mod!(check_f32, f32);
+make_ty_mod!(check_f64, f64);
+make_ty_mod!(check_f128, f128);
+
+fn main() {}