fixup serialization

Author: beccadax

include/swift/AST/Attr.h

@@ -2235,10 +2235,11 @@ class ObjCImplementationAttr final : public DeclAttribute {
   Identifier CategoryName;
 
   ObjCImplementationAttr(Identifier CategoryName, SourceLoc AtLoc,
-                         SourceRange Range, bool Implicit = false)
+                         SourceRange Range, bool Implicit = false,
+                         bool isCategoryNameInvalid = false)
     : DeclAttribute(DAK_ObjCImplementation, AtLoc, Range, Implicit),
       CategoryName(CategoryName) {
-    Bits.ObjCImplementationAttr.isCategoryNameInvalid = false;
+    Bits.ObjCImplementationAttr.isCategoryNameInvalid = isCategoryNameInvalid;
   }
 
   bool isCategoryNameInvalid() const {

lib/Serialization/Deserialization.cpp

@@ -5052,6 +5052,20 @@ llvm::Error DeclDeserializer::deserializeDeclCommon() {
         break;
       }
 
+      case decls_block::ObjCImplementation_DECL_ATTR: {
+        bool isImplicit;
+        bool isCategoryNameInvalid;
+        uint64_t categoryNameID;
+        serialization::decls_block::ObjCImplementationDeclAttrLayout::
+            readRecord(scratch, isImplicit, isCategoryNameInvalid,
+                       categoryNameID);
+        Identifier categoryName = MF.getIdentifier(categoryNameID);
+        Attr = new (ctx) ObjCImplementationAttr(categoryName, SourceLoc(),
+                                                SourceRange(), isImplicit,
+                                                isCategoryNameInvalid);
+        break;
+      }
+
 #define SIMPLE_DECL_ATTR(NAME, CLASS, ...) \
       case decls_block::CLASS##_DECL_ATTR: { \
         bool isImplicit; \

lib/Serialization/Serialization.cpp

@@ -2683,7 +2683,7 @@ class Serializer::DeclSerializer : public DeclVisitor<DeclSerializer> {
       auto abbrCode =
           S.DeclTypeAbbrCodes[ObjCImplementationDeclAttrLayout::Code];
       ObjCImplementationDeclAttrLayout::emitRecord(S.Out, S.ScratchRecord,
-          abbrCode, theAttr->isInvalid(), theAttr->isCategoryNameInvalid(),
+          abbrCode, theAttr->isImplicit(), theAttr->isCategoryNameInvalid(),
           categoryNameID);
       return;
     }