disable isolation check for mach_timebase_info

Author: pvdrz

src/shims/time.rs

@@ -271,7 +271,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         let this = self.eval_context_mut();
 
         this.assert_target_os("macos", "mach_timebase_info");
-        this.check_no_isolation("`mach_timebase_info`")?;
 
         let info = this.deref_operand(info_op)?;