Revert of Convert SIMD wasm ops to runtime function calls

src/wasm/wasm-opcodes.cc

Index: src/wasm/wasm-opcodes.cc
diff --git a/src/wasm/wasm-opcodes.cc b/src/wasm/wasm-opcodes.cc
index 8f54207661363ca59b2fa41134d500cade481fa1..afb1eff36687a622a4bb62b3a118281d0af8c10a 100644
--- a/src/wasm/wasm-opcodes.cc
+++ b/src/wasm/wasm-opcodes.cc
@@ -68,27 +68,15 @@
 static const FunctionSig* kSimpleExprSigs[] = {
     nullptr, FOREACH_SIGNATURE(DECLARE_SIG_ENTRY)};
 
-#define DECLARE_SIMD_SIG_ENTRY(name, ...) &kSig_##name,
-
-static const FunctionSig* kSimdExprSigs[] = {
-    nullptr, FOREACH_SIMD_SIGNATURE(DECLARE_SIMD_SIG_ENTRY)};
-
 static byte kSimpleExprSigTable[256];
-static byte kSimdExprSigTable[256];
 
 // Initialize the signature table.
-static void InitSigTables() {
+static void InitSigTable() {
 #define SET_SIG_TABLE(name, opcode, sig) \
   kSimpleExprSigTable[opcode] = static_cast<int>(kSigEnum_##sig) + 1;
   FOREACH_SIMPLE_OPCODE(SET_SIG_TABLE);
   FOREACH_SIMPLE_MEM_OPCODE(SET_SIG_TABLE);
   FOREACH_ASMJS_COMPAT_OPCODE(SET_SIG_TABLE);
-#undef SET_SIG_TABLE
-  byte simd_index;
-#define SET_SIG_TABLE(name, opcode, sig) \
-  simd_index = opcode & 0xff;            \
-  kSimdExprSigTable[simd_index] = static_cast<int>(kSigEnum_##sig) + 1;
-  FOREACH_SIMD_OPCODE(SET_SIG_TABLE)
 #undef SET_SIG_TABLE
 }
 
@@ -96,26 +84,18 @@
  public:
   SigTable() {
     // TODO(ahaas): Move {InitSigTable} into the class.
-    InitSigTables();
+    InitSigTable();
   }
   FunctionSig* Signature(WasmOpcode opcode) const {
     return const_cast<FunctionSig*>(
         kSimpleExprSigs[kSimpleExprSigTable[static_cast<byte>(opcode)]]);
-  }
-  FunctionSig* SimdSignature(WasmOpcode opcode) const {
-    return const_cast<FunctionSig*>(
-        kSimdExprSigs[kSimdExprSigTable[static_cast<byte>(opcode & 0xff)]]);
   }
 };
 
 static base::LazyInstance<SigTable>::type sig_table = LAZY_INSTANCE_INITIALIZER;
 
 FunctionSig* WasmOpcodes::Signature(WasmOpcode opcode) {
-  if (opcode >> 8 == kSimdPrefix) {
-    return sig_table.Get().SimdSignature(opcode);
-  } else {
-    return sig_table.Get().Signature(opcode);
-  }
+  return sig_table.Get().Signature(opcode);
 }
 
 // TODO(titzer): pull WASM_64 up to a common header.