[turbofan] We never use Int64Constant for branch/select conditions.

src/compiler/common-operator-reducer.cc

Index: src/compiler/common-operator-reducer.cc
diff --git a/src/compiler/common-operator-reducer.cc b/src/compiler/common-operator-reducer.cc
index fad9b99aaa5fdfb0bee0886a7dfae197790eb6ce..2f486833c609c464d2995f466283ff42788b9c30 100644
--- a/src/compiler/common-operator-reducer.cc
+++ b/src/compiler/common-operator-reducer.cc
@@ -27,10 +27,6 @@ Decision DecideCondition(Node* const cond) {
       Int32Matcher mcond(cond);
       return mcond.Value() ? Decision::kTrue : Decision::kFalse;
     }
-    case IrOpcode::kInt64Constant: {
-      Int64Matcher mcond(cond);
-      return mcond.Value() ? Decision::kTrue : Decision::kFalse;
-    }
     case IrOpcode::kHeapConstant: {
       HeapObjectMatcher mcond(cond);
       return mcond.Value()->BooleanValue() ? Decision::kTrue : Decision::kFalse;