Add "--emit=link"

This avoids a strange linker error that we get with only "--emit=mir"
and "check-pass"

Author: Aaron1011

src/test/ui/trivial-bounds/trivial-bounds-inconsistent-associated-functions.rs

@@ -1,5 +1,5 @@
 // check-pass
-// compile-flags: --emit=mir
+// compile-flags: --emit=mir,link
 // Force mir to be emitted, to ensure that const
 // propagation doesn't ICE on a function
 // with an 'impossible' body. See issue #67696