[generators] Perform state dispatch in loop header.

src/interpreter/control-flow-builders.h

Index: src/interpreter/control-flow-builders.h
diff --git a/src/interpreter/control-flow-builders.h b/src/interpreter/control-flow-builders.h
index e4d376b9b21e90bdd1121589bcc28d6cc8de4924..3c87e86bd20701d55aaeb4f747d77bbb1340ffcb 100644
--- a/src/interpreter/control-flow-builders.h
+++ b/src/interpreter/control-flow-builders.h
@@ -82,16 +82,22 @@ class BlockBuilder final : public BreakableControlFlowBuilder {
 // their loop.
 class LoopBuilder final : public BreakableControlFlowBuilder {
  public:
-  explicit LoopBuilder(BytecodeArrayBuilder* builder)
+  explicit LoopBuilder(BytecodeArrayBuilder* builder, int yield_count)
       : BreakableControlFlowBuilder(builder),
+        yield_count(yield_count),
         continue_sites_(builder->zone()) {}
   ~LoopBuilder();
 
   void LoopHeader();
   void Condition() { builder()->Bind(&condition_); }
   void Next() { builder()->Bind(&next_); }
-  void JumpToHeader() { builder()->Jump(&loop_header_); }
-  void JumpToHeaderIfTrue() { builder()->JumpIfTrue(&loop_header_); }
+  void JumpToHeader();
+  void JumpToHeaderIfTrue() {
+    BytecodeLabel no_jump;
+    builder()->JumpIfFalse(&no_jump);
+    JumpToHeader();
+    builder()->Bind(&no_jump);
+  }
   void EndLoop();
 
   // This method is called when visiting continue statements in the AST.
@@ -102,6 +108,9 @@ class LoopBuilder final : public BreakableControlFlowBuilder {
   void ContinueIfUndefined() { EmitJumpIfUndefined(&continue_sites_); }
   void ContinueIfNull() { EmitJumpIfNull(&continue_sites_); }
 
+  // Number of yields inside the loop.
+  const int yield_count;
+
  private:
   void SetContinueTarget(const BytecodeLabel& continue_target);