[wasm] I added I64Eq to the Int64Lowering.

src/compiler/int64-lowering.cc

Index: src/compiler/int64-lowering.cc
diff --git a/src/compiler/int64-lowering.cc b/src/compiler/int64-lowering.cc
index 1b0ead5049c689dd61f20402548ca22d3065b387..b83ab2634521c5625047b12cd76f55defa49e8ee 100644
--- a/src/compiler/int64-lowering.cc
+++ b/src/compiler/int64-lowering.cc
@@ -293,6 +293,24 @@ void Int64Lowering::LowerNode(Node* node) {
     // kExprI64ShrU:
     // kExprI64ShrS:
     // kExprI64Eq:
+    case IrOpcode::kWord64Equal: {
+      DCHECK(node->InputCount() == 2);
+      Node* left = node->InputAt(0);
+      Node* right = node->InputAt(1);
+
+      Node* replacement = graph()->NewNode(

[titzer, 2016/02/23 15:49:30]

Can you add a 

TODO(wasm): Use explicit comparisons and && here?

Since we might want to explore that as a better codegen option. The TODO(wasm)
indicates that it's a performance enhancement and not a functionality problem.

+          machine()->Word32Equal(),
+          graph()->NewNode(
+              machine()->Word32Or(),
+              graph()->NewNode(machine()->Word32Xor(), GetReplacementLow(left),
+                               GetReplacementLow(right)),
+              graph()->NewNode(machine()->Word32Xor(), GetReplacementHigh(left),
+                               GetReplacementHigh(right))),
+          graph()->NewNode(common()->Int32Constant(0)));
+
+      ReplaceNode(node, replacement, nullptr);
+      break;
+    }
     // kExprI64Ne:
     // kExprI64LtS:
     // kExprI64LeS: