[turbofan] Remove case_count >= 3 limit for switch.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index c16cd31c69c07b38ea42f90308bd8eeb839c7598..b6faa306aae6287179d61a1435c464bb19c61c9c 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -593,7 +593,6 @@ void InstructionSelector::VisitControl(BasicBlock* block) {
       DCHECK_EQ(IrOpcode::kIfDefault, sw.default_branch->front()->opcode());
       // All other successors must be cases.
       sw.case_count = block->SuccessorCount() - 1;
-      DCHECK_LE(1u, sw.case_count);
       sw.case_branches = &block->successors().front();
       // Determine case values and their min/max.
       sw.case_values = zone()->NewArray<int32_t>(sw.case_count);