Revert of Remove SIMD.js from V8.

src/full-codegen/mips/full-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_MIPS
 
 // Note on Mips implementation:
 //
 // The result_register() for mips is the 'v0' register, which is defined
 // by the ABI to contain function return values. However, the first
@@ skipping 2616 matching lines @@
     __ LoadRoot(at, Heap::kNullValueRootIndex);
     __ Branch(if_true, eq, v0, Operand(at));
     STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
     __ GetObjectType(v0, v0, a1);
     __ Branch(if_false, lt, a1, Operand(FIRST_JS_RECEIVER_TYPE));
     // Check for callable or undetectable objects => false.
     __ lbu(a1, FieldMemOperand(v0, Map::kBitFieldOffset));
     __ And(a1, a1,
            Operand((1 << Map::kIsCallable) | (1 << Map::kIsUndetectable)));
     Split(eq, a1, Operand(zero_reg), if_true, if_false, fall_through);
+// clang-format off
+#define SIMD128_TYPE(TYPE, Type, type, lane_count, lane_type)    \
+  } else if (String::Equals(check, factory->type##_string())) {  \
+    __ JumpIfSmi(v0, if_false);                                  \
+    __ lw(v0, FieldMemOperand(v0, HeapObject::kMapOffset));      \
+    __ LoadRoot(at, Heap::k##Type##MapRootIndex);                \
+    Split(eq, v0, Operand(at), if_true, if_false, fall_through);
+  SIMD128_TYPES(SIMD128_TYPE)
+#undef SIMD128_TYPE
+    // clang-format on
   } else {
     if (if_false != fall_through) __ jmp(if_false);
   }
   context()->Plug(if_true, if_false);
 }
 
 
 void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   Comment cmnt(masm_, "[ CompareOperation");
 
@@ skipping 211 matching lines @@
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OnStackReplacement()->entry()));
   return ON_STACK_REPLACEMENT;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS