Moving more build-pass tests to check-pass

One or two tests became build-pass without the FIXME because they really
needed build-pass (were failing without it).

Helps with #62277

src/test/ui/loops/loops-reject-duplicate-labels-2.rs

@@ -1,4 +1,4 @@
-// build-pass (FIXME(62277): could be check-pass?)
+// check-pass
 
 // ignore-tidy-linelength
 

src/test/ui/loops/loops-reject-duplicate-labels.rs

@@ -1,4 +1,4 @@
-// build-pass (FIXME(62277): could be check-pass?)
+// check-pass
 
 // ignore-tidy-linelength
 

src/test/ui/loops/loops-reject-labels-shadowing-lifetimes.rs

@@ -1,7 +1,7 @@
 // Issue #21633: reject duplicate loop labels in function bodies.
 // This is testing interaction between lifetime-params and labels.
 
-// build-pass (FIXME(62277): could be check-pass?)
+// check-pass
 
 #![allow(dead_code, unused_variables)]
 

src/test/ui/loops/loops-reject-lifetime-shadowing-label.rs

@@ -1,4 +1,4 @@
-// build-pass (FIXME(62277): could be check-pass?)
+// check-pass
 
 #![allow(dead_code, unused_variables)]