Improve the `GCC_VERSION_AT_LEAST(major, minor)` macro to `GCC_VERSION_AT_LEAST(major, minor, patch)`

[mikkoi]

I mean to improve the GCC_VERSION_AT_LEAST(major, minor) macro to GCC_VERSION_AT_LEAST(major, minor, patch) because the patch number is useful in some circumstances, such as here.

Originally posted by @mikkoi in #212

[mikkoi]

/**
 * __GNUC_PATCHLEVEL__ is new to GCC 3.0;
 * it is also present in the widely-used development snapshots leading up to 3.0
 * (which identify themselves as GCC 2.96 or 2.97, depending on which snapshot you have).
 *
 * https://stackoverflow.com/questions/1936719/what-are-the-gcc-predefined-macros-for-the-compilers-version-number/1936745#1936745
 */

#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
#define GCC_VERSION_AT_LEAST(major, minor, patch) \
((__GNUC__ > (major)) || \
 (__GNUC__ == (major) && __GNUC_MINOR__ > (minor)) || \
 (__GNUC__ == (major) && __GNUC_MINOR__ == (minor) && __GNUC_PATCHLEVEL__ >= (patch)) )
#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
#define GCC_VERSION_AT_LEAST(major, minor, patch) \
((__GNUC__ > (major)) || \
 (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
#else
#define GCC_VERSION_AT_LEAST(major, minor, patch) 0
#12