[turbofan] Implemented the TruncateFloat64ToUint64 TurboFan operator.

src/compiler/arm64/code-generator-arm64.cc

Index: src/compiler/arm64/code-generator-arm64.cc
diff --git a/src/compiler/arm64/code-generator-arm64.cc b/src/compiler/arm64/code-generator-arm64.cc
index 90686a79d2d9ae2f97fbf8304c794a3e7d6a2cbc..6f3ba050bbf76284dc2904bf218bc31c84ff2d8f 100644
--- a/src/compiler/arm64/code-generator-arm64.cc
+++ b/src/compiler/arm64/code-generator-arm64.cc
@@ -1000,6 +1000,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kArm64Float64ToInt64:
       __ Fcvtzs(i.OutputRegister64(), i.InputDoubleRegister(0));
       break;
+    case kArm64Float64ToUint64:
+      __ Fcvtzu(i.OutputRegister64(), i.InputDoubleRegister(0));
+      break;
     case kArm64Int32ToFloat64:
       __ Scvtf(i.OutputDoubleRegister(), i.InputRegister32(0));
       break;