[cff, truetype] Integer overflows.

Reported as

  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2144
  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2151
  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2153
  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2173
  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2186

* src/cff/cf2blues.c (cf2_blues_init): Use SUB_INT32.

* src/truetype/ttinterp.c (Round_None, Round_To_Grid,
Round_To_Half_Grid, Round_Down_To_Grid, Round_Up_To_Grid,
Round_To_Double_Grid, Round_Super, Round_Super_45): Use ADD_LONG,
SUB_LONG, NEG_LONG, FT_PIX_ROUND_LONG, FT_PIX_CEIL_LONG,
FT_PAD_ROUND_LONG
(Ins_SxVTL, Ins_MIRP): Use SUB_LONG.
(_iup_worker_shift): Use SUB_LONG and ADD_LONG.
3 files changed