[turbofan] Add support for relevant ES6 type conversion intrinsics.

test/cctest/compiler/test-js-typed-lowering.cc

Index: test/cctest/compiler/test-js-typed-lowering.cc
diff --git a/test/cctest/compiler/test-js-typed-lowering.cc b/test/cctest/compiler/test-js-typed-lowering.cc
index ae38bbfdac5e333cde98f79ce6f42a3ed7db8bca..cc799448d3b03a254eb63a7ed0169b72f061afed 100644
--- a/test/cctest/compiler/test-js-typed-lowering.cc
+++ b/test/cctest/compiler/test-js-typed-lowering.cc
@@ -544,8 +544,7 @@ TEST(JSToString1) {
 
   {  // ToString(boolean)
     Node* r = R.ReduceUnop(op, Type::Boolean());
-    // TODO(titzer): could be a branch
-    CHECK_EQ(IrOpcode::kJSToString, r->opcode());
+    CHECK_EQ(IrOpcode::kSelect, r->opcode());
   }
 
   {  // ToString(number)
@@ -573,8 +572,9 @@ TEST(JSToString_replacement) {
 
   for (size_t i = 0; i < arraysize(types); i++) {
     Node* n = R.Parameter(types[i]);
-    Node* c = R.graph.NewNode(R.javascript.ToString(), n, R.context(),
-                              R.start(), R.start());
+    Node* c =
+        R.graph.NewNode(R.javascript.ToString(), n, R.context(),
+                        R.EmptyFrameState(R.context()), R.start(), R.start());
     Node* effect_use = R.UseForEffect(c);
     Node* add = R.graph.NewNode(R.simplified.ReferenceEqual(Type::Any()), n, c);