Add missing revision mcdc to a coverage test

Zalathar · Zalathar · commit c333428885e1 · 2024-05-03T17:26:45.000+10:00
This test has header directives that refer to revision `[mcdc]`, which was
never actually declared in the revisions line.
diff --git a/tests/ui/instrument-coverage/coverage-options.rs b/tests/ui/instrument-coverage/coverage-options.rs
@@ -1,4 +1,4 @@
-//@ revisions: block branch bad
+//@ revisions: block branch mcdc bad
 //@ compile-flags -Cinstrument-coverage -Zno-profiler-runtime
 
 //@ [block] check-pass

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-//@ revisions: block branch bad`
	`1`	`+//@ revisions: block branch mcdc bad`
`2`	`2`	`//@ compile-flags -Cinstrument-coverage -Zno-profiler-runtime`
`3`	`3`
`4`	`4`	`//@ [block] check-pass`