Add emerald target to STAGE0_MISSING_TARGETS

Author: Amjad50

src/bootstrap/src/core/sanity.rs

@@ -35,6 +35,7 @@ const STAGE0_MISSING_TARGETS: &[&str] = &[
     // just a dummy comment so the list doesn't get onelined
     "aarch64-apple-visionos",
     "aarch64-apple-visionos-sim",
+    "x86_64-unknown-emerald",
 ];
 
 impl Finder {