Revert of Remove SIMD.js from V8.

src/full-codegen/ppc/full-codegen-ppc.cc

 // Copyright 2014 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_PPC
 
 #include "src/ast/compile-time-value.h"
 #include "src/ast/scopes.h"
 #include "src/builtins/builtins-constructor.h"
 #include "src/code-factory.h"
@@ skipping 2603 matching lines @@
     __ CompareRoot(r3, Heap::kNullValueRootIndex);
     __ beq(if_true);
     STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
     __ CompareObjectType(r3, r3, r4, FIRST_JS_RECEIVER_TYPE);
     __ blt(if_false);
     // Check for callable or undetectable objects => false.
     __ lbz(r4, FieldMemOperand(r3, Map::kBitFieldOffset));
     __ andi(r0, r4,
             Operand((1 << Map::kIsCallable) | (1 << Map::kIsUndetectable)));
     Split(eq, if_true, if_false, fall_through, cr0);
+// clang-format off
+#define SIMD128_TYPE(TYPE, Type, type, lane_count, lane_type)   \
+  } else if (String::Equals(check, factory->type##_string())) { \
+    __ JumpIfSmi(r3, if_false);                                 \
+    __ LoadP(r3, FieldMemOperand(r3, HeapObject::kMapOffset));    \
+    __ CompareRoot(r3, Heap::k##Type##MapRootIndex);            \
+    Split(eq, if_true, if_false, fall_through);
+  SIMD128_TYPES(SIMD128_TYPE)
+#undef SIMD128_TYPE
+    // clang-format on
   } else {
     if (if_false != fall_through) __ b(if_false);
   }
   context()->Plug(if_true, if_false);
 }
 
 
 void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   Comment cmnt(masm_, "[ CompareOperation");
 
@@ skipping 202 matching lines @@
 
   DCHECK(Assembler::IsCrSet(Assembler::instr_at(cmp_address)));
 
   DCHECK(interrupt_address ==
          isolate->builtins()->OnStackReplacement()->entry());
   return ON_STACK_REPLACEMENT;
 }
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_TARGET_ARCH_PPC