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

src/compiler/instruction-codes.h

Index: src/compiler/instruction-codes.h
diff --git a/src/compiler/instruction-codes.h b/src/compiler/instruction-codes.h
index 6242e9804e2cbd510c0c3a8df5813b258b4c2f78..00b2733b3b3aa9eed4d16818e3e0cfe3e9b6f253 100644
--- a/src/compiler/instruction-codes.h
+++ b/src/compiler/instruction-codes.h
@@ -152,7 +152,8 @@ enum FlagsMode {
   kFlags_none = 0,
   kFlags_branch = 1,
   kFlags_deoptimize = 2,
-  kFlags_set = 3
+  kFlags_set = 3,
+  kFlags_trap = 4
 };
 
 V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
@@ -207,9 +208,9 @@ typedef int32_t InstructionCode;
 // the instruction.
 typedef BitField<ArchOpcode, 0, 8> ArchOpcodeField;
 typedef BitField<AddressingMode, 8, 5> AddressingModeField;
-typedef BitField<FlagsMode, 13, 2> FlagsModeField;
-typedef BitField<FlagsCondition, 15, 5> FlagsConditionField;
-typedef BitField<int, 20, 12> MiscField;
+typedef BitField<FlagsMode, 13, 3> FlagsModeField;
+typedef BitField<FlagsCondition, 16, 5> FlagsConditionField;
+typedef BitField<int, 21, 11> MiscField;
 
 }  // namespace compiler
 }  // namespace internal