Quite a mouthful of a macro name. Following some of the MFBT templates for versioning, something like:

#define CLANG_AT_LEAST(major, minor) \
  (CLANG_VERSION_MAJOR > (major) || (CLANG_VERSION_MAJOR == (major) && CLANG_VERSION_MINOR >= (minor)))

and then using #if CLANG_AT_LEAST(3, 3) later works better.