Emit internal decls record fields depend upon.

Default ctors and dtors of records that are implicitly called if a field is one such record may not appear anywhere in its parent AST node.

Fixes the remaining linking error from #12.

dmd2/cpp/calypso.h

@@ -166,6 +166,8 @@ class LangPlugin : public ::LangPlugin, public ::ForeignCodeGen
     void emitAdditionalClassSymbols(::ClassDeclaration *cd) override;
     void toInitClass(TypeClass* tc, LLValue* dst) override;
     void toPostNewClass(Loc& loc, TypeClass* tc, DValue* val) override;
+
+    void EmitInternalDeclsForFields(const clang::RecordDecl *RD);
 
     // ==== ==== ====
     PCH pch;

gen/cpp/cpptoir.cpp

@@ -688,6 +688,29 @@ void LangPlugin::toDefaultInitVarDeclaration(::VarDeclaration* vd)
     }
 }
 
+void LangPlugin::EmitInternalDeclsForFields(const clang::RecordDecl *RD)
+{
+    auto& Context = getASTContext();
+    auto& S = pch.AST->getSema();
+
+    InternalDeclEmitter Emitter(Context, *CGM);
+
+    auto Emit = [&] (clang::CXXMethodDecl *D) {
+        if (D && !D->isDeleted())
+            Emitter.Emit(D);
+    };
+
+    for (auto F: RD->fields())
+    {
+        auto FTyRec = F->getType()->getAsCXXRecordDecl();
+        if (!FTyRec)
+            continue;
+
+        Emit(S.LookupDefaultConstructor(FTyRec));
+        Emit(S.LookupDestructor(FTyRec));
+    }
+}
+
 void LangPlugin::toDefineStruct(::StructDeclaration* sd)
 {
     auto& S = pch.AST->getSema();
@@ -712,10 +735,16 @@ void LangPlugin::toDefineStruct(::StructDeclaration* sd)
 
     EmitStructor(S.LookupDefaultConstructor(_RD));
     EmitStructor(S.LookupCopyingConstructor(_RD, clang::Qualifiers::Const));
+
+    EmitInternalDeclsForFields(RD);
 }
 
 void LangPlugin::toDefineClass(::ClassDeclaration* cd)
 {
+    auto c_cd = static_cast<cpp::ClassDeclaration*>(cd);
+    auto RD = cast<clang::CXXRecordDecl>(c_cd->RD);
+
+    EmitInternalDeclsForFields(RD);
 }
 
 void LangPlugin::toDefineTemplateInstance(::TemplateInstance *inst)