[turbofan] Add TruncationMode for TruncateFloat64ToInt32.

src/compiler/mips/instruction-selector-mips.cc

Index: src/compiler/mips/instruction-selector-mips.cc
diff --git a/src/compiler/mips/instruction-selector-mips.cc b/src/compiler/mips/instruction-selector-mips.cc
index 52be8a9a2a5b81cf4ab971d6dc5911082626330b..c2420ac0d816cc3b7688658cb79c0bb207b3ec9e 100644
--- a/src/compiler/mips/instruction-selector-mips.cc
+++ b/src/compiler/mips/instruction-selector-mips.cc
@@ -391,6 +391,17 @@ void InstructionSelector::VisitTruncateFloat64ToFloat32(Node* node) {
 }
 
 
+void InstructionSelector::VisitTruncateFloat64ToInt32(Node* node) {
+  switch (TruncationModeOf(node->op())) {
+    case TruncationMode::kJavaScript:
+      return VisitRR(this, kArchTruncateDoubleToI, node);
+    case TruncationMode::kRoundToZero:
+      return VisitRR(this, kMipsTruncWD, node);
+  }
+  UNREACHABLE();
+}
+
+
 void InstructionSelector::VisitFloat32Add(Node* node) {
   VisitRRR(this, kMipsAddS, node);
 }