[ptr-compr] Add pointer compression state into flags hash

... in order to ensure that the serialized data is reusable between
ptr-compr and full-ptr V8s having the same version number.

Bug: chromium:1054248
Change-Id: Ibf793755fd7e2bab79ed707a3e63dbfb8c89c519
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2066980
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66399}

src/flags/flags.cc

@@ -594,9 +594,12 @@ static uint32_t flag_hash = 0;
 
 void ComputeFlagListHash() {
   std::ostringstream modified_args_as_string;
-#ifdef DEBUG
-  modified_args_as_string << "debug";
-#endif  // DEBUG
+  if (COMPRESS_POINTERS_BOOL) {
+    modified_args_as_string << "ptr-compr";
+  }
+  if (DEBUG_BOOL) {
+    modified_args_as_string << "debug";
+  }
   for (size_t i = 0; i < num_flags; ++i) {
     Flag* current = &flags[i];
     if (current->type() == Flag::TYPE_BOOL &&