Remove some leftovers of full-codegen's generators implementation.

src/ia32/assembler-ia32.h

Index: src/ia32/assembler-ia32.h
diff --git a/src/ia32/assembler-ia32.h b/src/ia32/assembler-ia32.h
index 79f412535431d205ca371cabf52c4acf61f4b0a9..ddee6961620249847783e53172f857a1c4935712 100644
--- a/src/ia32/assembler-ia32.h
+++ b/src/ia32/assembler-ia32.h
@@ -1434,9 +1434,6 @@ class Assembler : public AssemblerBase {
     return pc_offset() - label->pos();
   }
 
-  // Mark generator continuation.
-  void RecordGeneratorContinuation();
-
   // Mark address of a debug break slot.
   void RecordDebugBreakSlot(RelocInfo::Mode mode);