[cache] Replace `FT_PtrDist' with `FT_Offset'.
* src/cache/ftccache.h (FTC_NodeRec): `FT_Offset' (a.k.a. `size_t')
is a better choice for `hash' to hold a pointer than `FT_PtrDist'
(a.k.a. `ptrdiff_t'), especially since the latter is signed,
causing zillions of signedness warnings. [Note that `hash' was of
type `FT_UInt32' before the change to `FT_PtrDist.]
Update all users.
* src/cache/ftcbasic.c, src/cache/ftccache.c, src/cache/ftccmap.c,
src/cache/ftcglyph.c, src/cache/ftcglyph.h: Updated.
7 files changed