[wasm] Introduce the TrapIf and TrapUnless operators to generate trap code.

src/compiler/s390/instruction-selector-s390.cc

Index: src/compiler/s390/instruction-selector-s390.cc
diff --git a/src/compiler/s390/instruction-selector-s390.cc b/src/compiler/s390/instruction-selector-s390.cc
index 3c9502fd0914e0101b9c9c92bd1122ec31bb2c6a..4ffc2455d91e06e042e67479accfc9492c7953c6 100644
--- a/src/compiler/s390/instruction-selector-s390.cc
+++ b/src/compiler/s390/instruction-selector-s390.cc
@@ -1786,6 +1786,10 @@ void InstructionSelector::VisitDeoptimizeUnless(Node* node) {
   VisitWord32CompareZero(this, node, node->InputAt(0), &cont);
 }
 
+void InstructionSelector::VisitTrapIf(Node* node) { UNREACHABLE(); }
+
+void InstructionSelector::VisitTrapUnless(Node* node) { UNREACHABLE(); }
+
 void InstructionSelector::VisitSwitch(Node* node, const SwitchInfo& sw) {
   S390OperandGenerator g(this);
   InstructionOperand value_operand = g.UseRegister(node->InputAt(0));