VarC: cast ints (#3934) msvc is rightfully complaining that the types on the sides of the ternary are not matching: ``` C:\pango\subprojects\harfbuzz\src\OT\glyf\VarCompositeGlyph.hh(317): error C2446: ':': no conversion from 'const OT::HBUINT16' to 'const OT::HBUINT8' ```