Rollup merge of rust-lang#80069 - jyn514:core-assert, r=dtolnay

Test that `core::assert!` is valid

Closes rust-lang#55482.

r? `@dtolnay`

Author: JohnTitor

src/test/ui/no-std-macros.rs

@@ -0,0 +1,13 @@
+// compile-flags: --crate-type=lib
+// check-pass
+// issue #55482
+#![no_std]
+
+macro_rules! foo {
+    ($e:expr) => {
+        $crate::core::assert!($e);
+        $crate::core::assert_eq!($e, true);
+    };
+}
+
+pub fn foo() { foo!(true); }