[clang-tidy] Make deleted member functions public

Making them private was a way to hide the functions, we can
explicitly delete them, which give a better compilation error message as
well.

Also see: https://stackoverflow.com/q/55205874

Bug: v8:10488
Change-Id: I27cb7b9aa3d2b90e1c05c1f12585f94c746cbdb1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2233981
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68273}

src/trap-handler/handler-inside-posix.cc

@@ -60,15 +60,15 @@ class SigUnmaskStack {
     pthread_sigmask(SIG_UNBLOCK, &sigs, &old_mask_);
   }
 
-  ~SigUnmaskStack() { pthread_sigmask(SIG_SETMASK, &old_mask_, nullptr); }
-
- private:
-  sigset_t old_mask_;
-
   // We'd normally use DISALLOW_COPY_AND_ASSIGN, but we're avoiding a dependency
   // on base/macros.h
   SigUnmaskStack(const SigUnmaskStack&) = delete;
   void operator=(const SigUnmaskStack&) = delete;
+
+  ~SigUnmaskStack() { pthread_sigmask(SIG_SETMASK, &old_mask_, nullptr); }
+
+ private:
+  sigset_t old_mask_;
 };
 
 bool TryHandleSignal(int signum, siginfo_t* info, void* context) {