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

src/compiler/ia32/code-generator-ia32.cc

Index: src/compiler/ia32/code-generator-ia32.cc
diff --git a/src/compiler/ia32/code-generator-ia32.cc b/src/compiler/ia32/code-generator-ia32.cc
index abba38b306f75586dd16ae3ed2d1dafc722e49e2..318d136ecbfa07fca10caced88152e64278a7de5 100644
--- a/src/compiler/ia32/code-generator-ia32.cc
+++ b/src/compiler/ia32/code-generator-ia32.cc
@@ -1672,6 +1672,10 @@ void CodeGenerator::AssembleArchJump(RpoNumber target) {
   if (!IsNextInAssemblyOrder(target)) __ jmp(GetLabel(target));
 }
 
+void CodeGenerator::AssembleArchTrap(Instruction* instr,
+                                     FlagsCondition condition) {
+  UNREACHABLE();
+}
 
 // Assembles boolean materializations after an instruction.
 void CodeGenerator::AssembleArchBoolean(Instruction* instr,