[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..a84d9a669291e3d31f7466a72f81ba22425ebca0 100644
--- a/pkg/kernel/binary.md
+++ b/pkg/kernel/binary.md
@@ -332,7 +332,7 @@ type FunctionNode {
   FileOffset fileOffset;
   FileOffset fileEndOffset;
   Byte asyncMarker; // Index into AsyncMarker above.
-  Byte debuggable; // 1 for yes, 0 for no
+  Byte originalAsyncMarker; // Index into AsyncMarker above.
   List<TypeParameter> typeParameters;
   UInt requiredParameterCount;
   List<VariableDeclaration> positionalParameters;