Fix Modi and File count if there are more than 65535 modules/files.

These numbers are intended to be capped at 65535, but
`std::max<uint16_t>(UINT16_MAX, N)` always returns N for any N because
the expression is the same as `std::max((uint16_t)UINT16_MAX, (uint16_t)N)`.

llvm-svn: 287060