Enable the CHECK for near-jump displacement range in Release mode too.

src/x64/assembler-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 449 matching lines @@
     // Fix up last fixup on linked list.
     int last_imm32 = pos - (current + sizeof(int32_t));
     long_at_put(current, last_imm32);
   }
   while (L->is_near_linked()) {
     int fixup_pos = L->near_link_pos();
     int offset_to_next =
         static_cast<int>(*reinterpret_cast<int8_t*>(addr_at(fixup_pos)));
     ASSERT(offset_to_next <= 0);
     int disp = pos - (fixup_pos + sizeof(int8_t));
-    ASSERT(is_int8(disp));
+    CHECK(is_int8(disp));
     set_byte_at(fixup_pos, disp);
     if (offset_to_next < 0) {
       L->link_to(fixup_pos + offset_to_next, Label::kNear);
     } else {
       L->UnuseNear();
     }
   }
   L->bind_to(pos);
 }
 
@@ skipping 2560 matching lines @@
 bool RelocInfo::IsCodedSpecially() {
   // The deserializer needs to know whether a pointer is specially coded.  Being
   // specially coded on x64 means that it is a relative 32 bit address, as used
   // by branch instructions.
   return (1 << rmode_) & kApplyMask;
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64