Lift `FT_Int64` type to global (internal) FreeType use. * src/base/ftcalc.c (FT_Int64) [!FT_INT64]: Move declaration to... * include/freetype/config/integer-types.h: ... this file. (FT_UInt64) [!FT_INT64]: New structure. (FT_INT64_ZERO): New macro.