Ignore tests

the bool thing will be fixed by the validation I have planned, and we already ignored another test around modifing constants.

Author: RalfJung

tests/compile-fail/invalid_bool.rs

@@ -1,3 +1,5 @@
+//ignore FIXME (do some basic validation of invariants for all values in flight)
+
 fn main() {
     let b = unsafe { std::mem::transmute::<u8, bool>(2) };
     if b { unreachable!() } else { unreachable!() } //~ ERROR constant evaluation error

tests/compile-fail/modifying_constants.rs

@@ -1,3 +1,5 @@
+// ignore-test FIXME: we are not making these statics read-only any more?
+
 fn main() {
     let x = &1; // the `&1` is promoted to a constant, but it used to be that only the pointer is marked static, not the pointee
     let y = unsafe { &mut *(x as *const i32 as *mut i32) };