MSVC_BUILTIN       21 maint/gnulib/lib/ffsl.c #define MSVC_BUILTIN _BitScanForward
MSVC_BUILTIN       22 maint/gnulib/lib/ffsll.c # define MSVC_BUILTIN _BitScanForward64
MSVC_BUILTIN       35 maint/gnulib/lib/integer_length_l.c #  define MSVC_BUILTIN _BitScanReverse64
MSVC_BUILTIN       41 maint/gnulib/lib/integer_length_l.c # define MSVC_BUILTIN _BitScanReverse