[turbofan] Add backend support for float32.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 3c32b642adb4c2cb937d55f8fe2c2f782146c2cb..d7d8c8b6ddae4902d20af1350b710eb2fcf783e6 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -570,6 +570,8 @@ void InstructionSelector::VisitNode(Node* node) {
       return VisitInt64LessThan(node);
     case IrOpcode::kInt64LessThanOrEqual:
       return VisitInt64LessThanOrEqual(node);
+    case IrOpcode::kChangeFloat32ToFloat64:
+      return MarkAsDouble(node), VisitChangeFloat32ToFloat64(node);
     case IrOpcode::kChangeInt32ToFloat64:
       return MarkAsDouble(node), VisitChangeInt32ToFloat64(node);
     case IrOpcode::kChangeUint32ToFloat64:
@@ -582,6 +584,8 @@ void InstructionSelector::VisitNode(Node* node) {
       return VisitChangeInt32ToInt64(node);
     case IrOpcode::kChangeUint32ToUint64:
       return VisitChangeUint32ToUint64(node);
+    case IrOpcode::kTruncateFloat64ToFloat32:
+      return MarkAsDouble(node), VisitTruncateFloat64ToFloat32(node);
     case IrOpcode::kTruncateFloat64ToInt32:
       return VisitTruncateFloat64ToInt32(node);
     case IrOpcode::kTruncateInt64ToInt32: