work around rustc optimizations becoming too smart

ci.sh

@@ -25,7 +25,7 @@ function run_tests {
   ./miri test --locked
   if ! [ -n "${MIRI_TEST_TARGET+exists}" ]; then
     # Only for host architecture: tests with MIR optimizations
-    # FIXME:only testing level 1 because of <https://github.com/rust-lang/rust/issues/73223>.
+    # FIXME: only testing level 1 because of <https://github.com/rust-lang/rust/issues/73223>.
     MIRI_TEST_FLAGS="-Z mir-opt-level=1" ./miri test --locked
   fi
   # "miri test" has built the sysroot for us, now this should pass without

rust-version

@@ -1 +1 @@
-d2454643e137bde519786ee9e650c455d7ad6f34
+e114d6228b948ce056de0bcdec2603c8e89d3727

tests/compile-fail/invalid_bool.rs

@@ -2,7 +2,9 @@
 // Make sure we find these even with many checks disabled.
 // compile-flags: -Zmiri-disable-alignment-check -Zmiri-disable-stacked-borrows -Zmiri-disable-validation
 
+fn dont_optimize<T>(x: T) -> T { x }
+
 fn main() {
     let b = unsafe { std::mem::transmute::<u8, bool>(2) };
-    let _x = b == true; //~ ERROR interpreting an invalid 8-bit value as a bool: 0x02
+    let _x = b == dont_optimize(true); //~ ERROR interpreting an invalid 8-bit value as a bool: 0x02
 }