[wasm] Initial commit for the Int64Reducer.

test/cctest/wasm/wasm-run-utils.h

Index: test/cctest/wasm/wasm-run-utils.h
diff --git a/test/cctest/wasm/wasm-run-utils.h b/test/cctest/wasm/wasm-run-utils.h
index f855306763f36142b7e876bbb0ed461dc0ca5a38..cef31f34bf68944137519a2311bf20012541c394 100644
--- a/test/cctest/wasm/wasm-run-utils.h
+++ b/test/cctest/wasm/wasm-run-utils.h
@@ -12,6 +12,7 @@
 #include "src/base/utils/random-number-generator.h"
 
 #include "src/compiler/graph-visualizer.h"
+#include "src/compiler/int64-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/wasm-compiler.h"
 
@@ -236,6 +237,7 @@ inline void TestBuildingGraph(Zone* zone, JSGraph* jsgraph, FunctionEnv* env,
     str << ", msg = " << result.error_msg.get();
     FATAL(str.str().c_str());
   }
+  builder.Int64LoweringForTesting();

[titzer, 2016/02/03 15:36:29]

This wasn't really what I meant with my earlier comment, but it's OK. You can
just inline this now. We can make it nicer in a later CL.

   if (FLAG_trace_turbo_graph) {
     OFStream os(stdout);
     os << AsRPO(*jsgraph->graph());