[NFC][clang][extract-api] Add missing virtual anchors

Add missing virtual method anchors for structs in ExtractAPI/API.h

Author: zixu-w

clang/include/clang/ExtractAPI/API.h

@@ -142,6 +142,9 @@ struct EnumConstantRecord : APIRecord {
   static bool classof(const APIRecord *Record) {
     return Record->getKind() == RK_EnumConstant;
   }
+
+private:
+  virtual void anchor();
 };
 
 /// This holds information associated with enums.
@@ -157,6 +160,9 @@ struct EnumRecord : APIRecord {
   static bool classof(const APIRecord *Record) {
     return Record->getKind() == RK_Enum;
   }
+
+private:
+  virtual void anchor();
 };
 
 /// This holds information associated with struct fields.
@@ -171,6 +177,9 @@ struct StructFieldRecord : APIRecord {
   static bool classof(const APIRecord *Record) {
     return Record->getKind() == RK_StructField;
   }
+
+private:
+  virtual void anchor();
 };
 
 /// This holds information associated with structs.
@@ -187,6 +196,9 @@ struct StructRecord : APIRecord {
   static bool classof(const APIRecord *Record) {
     return Record->getKind() == RK_Struct;
   }
+
+private:
+  virtual void anchor();
 };
 
 /// APISet holds the set of API records collected from given inputs.

clang/lib/ExtractAPI/API.cpp

@@ -131,3 +131,7 @@ StringRef APISet::copyString(StringRef String) {
 APIRecord::~APIRecord() {}
 
 void GlobalRecord::anchor() {}
+void EnumConstantRecord::anchor() {}
+void EnumRecord::anchor() {}
+void StructFieldRecord::anchor() {}
+void StructRecord::anchor() {}