[subset] when dropping hints, clear hint related fields in maxp.

BASE table

[subset] Drop hints

[subset] During os2 subsetting update ulUnicodeRange[]c

DEFINE_SIZE_MIN is to be used only in rare cases. For fixed-size structs
we want DEFINE_SIZE_STATIC.

We always just used "unsigned int" for counter values. There's
no use for uint16_t outside of a struct.

Also, no need for explict casting where implicit does.

Ops, this was done for testing