Auto merge of #82159 - BoxyUwU:uwu, r=varkor

Use correct param_env in conservative_is_privately_uninhabited

cc `@lcnr`
r? `@varkor` since this is your FIXME that was removed ^^

src/test/ui/const-generics/conservative_is_privately_uninhabited_uses_correct_param_env-1.rs

@@ -0,0 +1,27 @@
+// run-pass
+#![feature(const_generics, const_evaluatable_checked)]
+#![allow(incomplete_features)]
+
+// This tests that the `conservative_is_privately_uninhabited` fn doesn't cause
+// ICEs by trying to evaluate `T::ASSOC` with an incorrect `ParamEnv`.
+
+trait Foo {
+    const ASSOC: usize = 1;
+}
+
+struct Iced<T: Foo>(T, [(); T::ASSOC])
+where
+    [(); T::ASSOC]: ;
+
+impl Foo for u32 {}
+
+fn foo<T: Foo>()
+where
+    [(); T::ASSOC]: ,
+{
+    let _iced: Iced<T> = return;
+}
+
+fn main() {
+    foo::<u32>();
+}

src/test/ui/const-generics/conservative_is_privately_uninhabited_uses_correct_param_env-2.rs

@@ -0,0 +1,20 @@
+// run-pass
+#![feature(const_generics, const_evaluatable_checked)]
+#![allow(incomplete_features)]
+
+// This tests that the `conservative_is_privately_uninhabited` fn doesn't cause
+// ICEs by trying to evaluate `T::ASSOC` with an incorrect `ParamEnv`.
+
+trait Foo {
+    const ASSOC: usize = 1;
+}
+
+struct Iced<T: Foo>(T, [(); T::ASSOC])
+where
+    [(); T::ASSOC]: ;
+
+impl Foo for u32 {}
+
+fn main() {
+    let _iced: Iced<u32> = return;
+}