deps: cherry-pick 8bfbe25 from upstream V8

Original commit message:

    [compiler] Fix typing of NumberToString operator.

    It must be monotone.

    R=bmeurer@chromium.org

    Bug: v8:7354
    Change-Id: I08dcd3333518029eef08c074c2b91b5c20ad699e
    Reviewed-on: https://chromium-review.googlesource.com/880982
    Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
    Commit-Queue: Georg Neis <neis@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#50801}

Refs: https://github.com/v8/v8/commit/8bfbe25a7cbe359f40c4182d64ef75d9795ee085

PR-URL: https://github.com/nodejs/node/pull/18453
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yang Guo <yangguo@chromium.org>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

common.gypi

@@ -27,7 +27,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.1',
+    'v8_embedder_string': '-node.2',
 
     # Enable disassembler for `--print-code` v8 options
     'v8_enable_disassembler': 1,

deps/v8/src/compiler/operation-typer.cc

@@ -507,7 +507,7 @@ Type* OperationTyper::NumberToInt32(Type* type) {
 
 Type* OperationTyper::NumberToString(Type* type) {
   DCHECK(type->Is(Type::Number()));
-
+  if (type->IsNone()) return type;
   if (type->Is(Type::NaN())) return singleton_NaN_string_;
   if (type->Is(cache_.kZeroOrMinusZero)) return singleton_zero_string_;
   return Type::SeqString();