Added hasUnalignedFields helper to check if a type has unaligned fields - as per request from fvbommel. Result is cached in TypeStruct.

dmd2/mtype.h

@@ -628,6 +628,11 @@ struct TypeStruct : Type
 #endif
 
     type *toCtype();
+
+    // LDC
+    // cache the hasUnalignedFields check
+    // 0 = not checked, 1 = aligned, 2 = unaligned
+    int unaligned;
 };
 
 struct TypeEnum : Type