[Kernel] replace function debuggable field with originalAsyncMarker field

pkg/kernel/binary.md

Index: pkg/kernel/binary.md
diff --git a/pkg/kernel/binary.md b/pkg/kernel/binary.md
index 60596908fead59a521a0057dafb462780b73ff1e..78ca7a05057242653d1aed85082fe70923a6b474 100644
--- a/pkg/kernel/binary.md
+++ b/pkg/kernel/binary.md
@@ -323,7 +323,8 @@ enum AsyncMarker {
   Sync,
   SyncStar,
   Async,
-  AsyncStar
+  AsyncStar,
+  SyncYielding
 }
 */
 
@@ -332,7 +333,7 @@ type FunctionNode {
   FileOffset fileOffset;
   FileOffset fileEndOffset;
   Byte asyncMarker; // Index into AsyncMarker above.
-  Byte debuggable; // 1 for yes, 0 for no
+  Byte dartAsyncMarker; // Index into AsyncMarker above.
   List<TypeParameter> typeParameters;
   UInt requiredParameterCount;
   List<VariableDeclaration> positionalParameters;