Use a const ParamEnv when in default_method_body_is_const

src/test/ui/rfc-2632-const-trait-impl/default-method-body-is-const-body-checking.rs

@@ -0,0 +1,17 @@
+#![feature(const_fn_trait_bound)]
+#![feature(const_trait_impl)]
+
+trait Tr {}
+impl Tr for () {}
+
+const fn foo<T>() where T: ~const Tr {}
+
+pub trait Foo {
+    #[default_method_body_is_const]
+    fn foo() {
+        foo::<()>();
+        //~^ ERROR the trait bound `(): Tr` is not satisfied
+    }
+}
+
+fn main() {}

src/test/ui/rfc-2632-const-trait-impl/default-method-body-is-const-body-checking.stderr

@@ -0,0 +1,19 @@
+error[E0277]: the trait bound `(): Tr` is not satisfied
+  --> $DIR/default-method-body-is-const-body-checking.rs:12:15
+   |
+LL |         foo::<()>();
+   |               ^^ the trait `Tr` is not implemented for `()`
+   |
+note: required by a bound in `foo`
+  --> $DIR/default-method-body-is-const-body-checking.rs:7:28
+   |
+LL | const fn foo<T>() where T: ~const Tr {}
+   |                            ^^^^^^^^^ required by this bound in `foo`
+help: consider introducing a `where` bound, but there might be an alternative better way to express this requirement
+   |
+LL | pub trait Foo where (): Tr {
+   |               ++++++++++++
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.