Introduce bytecodes for assisting generator suspend and resume.

src/compiler/code-assembler.cc

Index: src/compiler/code-assembler.cc
diff --git a/src/compiler/code-assembler.cc b/src/compiler/code-assembler.cc
index b756ac4dea68b0f797a44dd32f173bc0529b419b..26280eb2d72a9a53afd528cccaf159b943a9f642 100644
--- a/src/compiler/code-assembler.cc
+++ b/src/compiler/code-assembler.cc
@@ -176,6 +176,13 @@ Node* CodeAssembler::ChangeUint32ToWord(Node* value) {
   return value;
 }
 
+Node* CodeAssembler::ChangeInt32ToWord(Node* value) {
+  if (raw_assembler_->machine()->Is64()) {
+    value = raw_assembler_->ChangeInt32ToInt64(value);
+  }
+  return value;
+}
+
 #define DEFINE_CODE_ASSEMBLER_UNARY_OP(name) \
   Node* CodeAssembler::name(Node* a) { return raw_assembler_->name(a); }
 CODE_ASSEMBLER_UNARY_OP_LIST(DEFINE_CODE_ASSEMBLER_UNARY_OP)