Merge V8 at 2.5.9.20

Pull in the latest V8 for various stability fixes.

Note that this deviates from the Chromium 9.0.597.x branch.

Bug: 3483676

Change-Id: Ic5178f532775218e1c87a71c54995c2820604cb3
diff --git a/src/arm/codegen-arm.cc b/src/arm/codegen-arm.cc
index 79e577b..469d41f 100644
--- a/src/arm/codegen-arm.cc
+++ b/src/arm/codegen-arm.cc
@@ -1150,7 +1150,7 @@
   }
   // Check that the *signed* result fits in a smi. Not necessary for AND, SAR
   // if the shift if more than 0 or SHR if the shit is more than 1.
-  if (!( (op_ == Token::AND) ||
+  if (!( (op_ == Token::AND && value_ >= 0) ||
         ((op_ == Token::SAR) && (shift_value > 0)) ||
         ((op_ == Token::SHR) && (shift_value > 1)))) {
     __ add(r3, int32, Operand(0x40000000), SetCC);
@@ -1411,8 +1411,10 @@
           default: UNREACHABLE();
         }
         deferred->BindExit();
-        TypeInfo result_type =
-            (op == Token::BIT_AND) ? TypeInfo::Smi() : TypeInfo::Integer32();
+        TypeInfo result_type = TypeInfo::Integer32();
+        if (op == Token::BIT_AND && int_value >= 0) {
+          result_type = TypeInfo::Smi();
+        }
         frame_->EmitPush(tos, result_type);
       }
       break;
diff --git a/src/version.cc b/src/version.cc
index fbbfe59..3806e68 100644
--- a/src/version.cc
+++ b/src/version.cc
@@ -35,7 +35,7 @@
 #define MAJOR_VERSION     2
 #define MINOR_VERSION     5
 #define BUILD_NUMBER      9
-#define PATCH_LEVEL       19
+#define PATCH_LEVEL       20
 #define CANDIDATE_VERSION false
 
 // Define SONAME to have the SCons build the put a specific SONAME into the