This page list notable options when building mingw-w64 from source
--enable-secure-api - Allows the use of *_s by default --with-default-win32-winnt - sets the default _WINT32_WINNT value, defaults to 0x502. Do not change if you do not understand the implications. --enable-secure-api - Option to install DirectX SDK and Device Driver SDK.
--enable-experimental - Enable 128-bit and decimal float printf