CMakeLists: Make -Wreorder a compile-time error

This can result in silent logic bugs within code, and given the amount
of times these kind of warnings are caused, they should be flagged at
compile-time so no new code is submitted with them.

src/CMakeLists.txt

@@ -53,6 +53,7 @@ if (MSVC)
 else()
     add_compile_options(
         -Wall
+        -Werror=reorder
         -Wno-attributes
     )