[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 6bc41f47dfcabdd1f14bb9b10847eb8d8bf0bb61..19ba51aa0e76b9f3e612bc8b2496cffee88a4ce4 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: