Revert of Remove SIMD.js from V8.

src/ppc/interface-descriptors-ppc.cc

Index: src/ppc/interface-descriptors-ppc.cc
diff --git a/src/ppc/interface-descriptors-ppc.cc b/src/ppc/interface-descriptors-ppc.cc
index ed03094dbd6e05c76eeb4f3eb8420202dc1e3ee6..875873f0dc5733d8c88250fe75fbf88dff0d58b4 100644
--- a/src/ppc/interface-descriptors-ppc.cc
+++ b/src/ppc/interface-descriptors-ppc.cc
@@ -195,6 +195,14 @@
   data->InitializePlatformSpecific(0, nullptr, nullptr);
 }
 
+#define SIMD128_ALLOC_DESC(TYPE, Type, type, lane_count, lane_type) \
+  void Allocate##Type##Descriptor::InitializePlatformSpecific(      \
+      CallInterfaceDescriptorData* data) {                          \
+    data->InitializePlatformSpecific(0, nullptr, nullptr);          \
+  }
+SIMD128_TYPES(SIMD128_ALLOC_DESC)
+#undef SIMD128_ALLOC_DESC
+
 void ArrayConstructorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // kTarget, kNewTarget, kActualArgumentsCount, kAllocationSite