[turbofan] Implemented the TruncateFloat32ToInt64 TurboFan operator.

src/compiler/mips64/instruction-selector-mips64.cc

Index: src/compiler/mips64/instruction-selector-mips64.cc
diff --git a/src/compiler/mips64/instruction-selector-mips64.cc b/src/compiler/mips64/instruction-selector-mips64.cc
index c98d871204573e36e66cbcec12e80cc1c7e2d2fe..5a32bb078b2b7fb3bd2fe4a1490376403321d55d 100644
--- a/src/compiler/mips64/instruction-selector-mips64.cc
+++ b/src/compiler/mips64/instruction-selector-mips64.cc
@@ -731,6 +731,11 @@ void InstructionSelector::VisitChangeFloat64ToUint32(Node* node) {
 }
 
 
+void InstructionSelector::VisitTruncateFloat32ToInt64(Node* node) {
+  VisitRR(this, kMips64TruncLS, node);
+}
+
+
 void InstructionSelector::VisitTruncateFloat64ToInt64(Node* node) {
   VisitRR(this, kMips64TruncLD, node);
 }