Eliminate the need for TypeFunction::funcdecl

dmd2/declaration.h

@@ -915,7 +915,7 @@ struct FuncDeclaration : Declaration
     virtual FuncDeclaration *toAliasFunc() { return this; }
 
 #if IN_LLVM
-    // LDC stuff
+    IrFuncTy irFty;
 
     /// Codegen traversal
     void codegen(Ir* ir);

dmd2/mtype.h

@@ -744,8 +744,7 @@ struct TypeFunction : TypeNext
     Expression *defaultInit(Loc loc);
 
 #if IN_LLVM
-    // LDC
-    IrFuncTy fty;
+    IrFuncTy irFty;
 
     FuncDeclaration* funcdecl;
 #endif
@@ -778,6 +777,10 @@ struct TypeDelegate : TypeNext
 #if IN_DMD
     type *toCtype();
 #endif
+
+#if IN_LLVM
+    IrFuncTy irFty;
+#endif
 };
 
 struct TypeQualified : Type