MIPS64: Port `[turbofan] Initial Word64 support in representation selection.`

Port 6346cdb6

Change-Id: I397ff152f363a3f0345105fbdf5d939bc3245fb4
Reviewed-on: https://chromium-review.googlesource.com/1225707Reviewed-by: Sreten Kovacevic <skovacevic@wavecomp.com>
Commit-Queue: Sreten Kovacevic <skovacevic@wavecomp.com>
Cr-Commit-Position: refs/heads/master@{#55911}

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

@@ -1239,6 +1239,9 @@ void InstructionSelector::VisitChangeFloat64ToInt32(Node* node) {
   VisitRR(this, kMips64TruncWD, node);
 }
 
+void InstructionSelector::VisitChangeFloat64ToInt64(Node* node) {
+  VisitRR(this, kMips64TruncLD, node);
+}
 
 void InstructionSelector::VisitChangeFloat64ToUint32(Node* node) {
   VisitRR(this, kMips64TruncUwD, node);