Fix some tests failing in --pass check mode

Author: petrochenkov

src/test/ui/consts/array-literal-index-oob.rs

@@ -1,5 +1,5 @@
 // build-pass
-// ignore-pass (emit codegen-time warnings and verify that they are indeed warnings and not errors)
+// ignore-pass (test emits codegen-time warnings and verifies that they are not errors)
 
 #![warn(const_err, unconditional_panic)]
 

src/test/ui/consts/const-eval/promoted_errors.rs

@@ -4,7 +4,7 @@
 //[opt_with_overflow_checks]compile-flags: -C overflow-checks=on -O
 
 // build-pass
-// ignore-pass (emit codegen-time warnings and verify that they are indeed warnings and not errors)
+// ignore-pass (test emits codegen-time warnings and verifies that they are not errors)
 
 #![warn(const_err, arithmetic_overflow, unconditional_panic)]
 

src/test/ui/lint/lint-exceeding-bitshifts.rs

@@ -2,8 +2,8 @@
 //[noopt]compile-flags: -C opt-level=0
 //[opt]compile-flags: -O
 //[opt_with_overflow_checks]compile-flags: -C overflow-checks=on -O
-
 // build-pass
+// ignore-pass (test emits codegen-time warnings and verifies that they are not errors)
 
 #![crate_type="lib"]
 #![warn(arithmetic_overflow, const_err)]