[turbofan] Add proper conversion operators for int32<->int64.

test/compiler-unittests/arm64/instruction-selector-arm64-unittest.cc

Index: test/compiler-unittests/arm64/instruction-selector-arm64-unittest.cc
diff --git a/test/compiler-unittests/arm64/instruction-selector-arm64-unittest.cc b/test/compiler-unittests/arm64/instruction-selector-arm64-unittest.cc
index 2a86924248054f530b32e426c2a8fd0857d9a453..e0de59060ae4aca8ab88a8cd841074dd74f61883 100644
--- a/test/compiler-unittests/arm64/instruction-selector-arm64-unittest.cc
+++ b/test/compiler-unittests/arm64/instruction-selector-arm64-unittest.cc
@@ -6,8 +6,6 @@
 
 #include "test/compiler-unittests/instruction-selector-unittest.h"
 
-#include "test/cctest/compiler/instruction-selector-tester.h"
-
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ -128,6 +126,37 @@ TEST_F(InstructionSelectorTest, MulDivWithParameter) {
   }
 }
 
+
+// -----------------------------------------------------------------------------
+// Conversions.
+
+
+TEST_F(InstructionSelectorTest, ChangeInt32ToInt64WithParameter) {
+  StreamBuilder m(this, kMachInt64, kMachInt32);
+  m.Return(m.ChangeInt32ToInt64(m.Parameter(0)));
+  Stream s = m.Build();
+  ASSERT_EQ(1U, s.size());
+  EXPECT_EQ(kArm64Sxtw, s[0]->arch_opcode());
+}
+
+
+TEST_F(InstructionSelectorTest, ChangeUint32ToUint64WithParameter) {
+  StreamBuilder m(this, kMachUint64, kMachUint32);
+  m.Return(m.ChangeUint32ToUint64(m.Parameter(0)));
+  Stream s = m.Build();
+  ASSERT_EQ(1U, s.size());
+  EXPECT_EQ(kArm64Mov32, s[0]->arch_opcode());
+}
+
+
+TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithParameter) {
+  StreamBuilder m(this, kMachInt32, kMachInt64);
+  m.Return(m.TruncateInt64ToInt32(m.Parameter(0)));
+  Stream s = m.Build();
+  ASSERT_EQ(1U, s.size());
+  EXPECT_EQ(kArm64Mov32, s[0]->arch_opcode());
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8