deps: V8: backport c4d06ba586f3

Original commit message:

    [loong64][compiler] Extend Word64Select instruction functionality

    Change-Id: Iba762777642d2d2d3aa904f9afc1e9005139992e
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/7801520
    Reviewed-by: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
    Commit-Queue: Liu Yu <liuyu@loongson.cn>
    Reviewed-by: Darius Mercadier <dmercadier@chromium.org>
    Auto-Submit: Liu Yu <liuyu@loongson.cn>
    Cr-Commit-Position: refs/heads/main@{#107619}

Refs: v8/v8@c4d06ba
Co-authored-by: liujiahui <liujiahui@loongson.cn>

Author: LiuYu3966

common.gypi

@@ -40,7 +40,7 @@
 
     # 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.20',
+    'v8_embedder_string': '-node.21',
 
     ##### V8 defaults for Node.js #####
 

deps/v8/src/compiler/backend/loong64/code-generator-loong64.cc

@@ -1363,10 +1363,14 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kLoong64Sub_d:
       __ Sub_d(i.OutputRegister(), i.InputRegister(0), i.InputOperand(1));
       break;
-    case kLoong64SubOvf_d:
+    case kLoong64SubOvf_d: {
+      UseScratchRegisterScope temps(masm());
+      DCHECK(temps.hasAvailable());
+      temps.Exclude(t8);
       __ SubOverflow_d(i.OutputRegister(), i.InputRegister(0),
                        i.InputOperand(1), t8);
       break;
+    }
     case kLoong64Mul_w:
       __ Mul_w(i.OutputRegister(), i.InputRegister(0), i.InputOperand(1));
       break;