[lld-macho] Don't use arrays as template parameters

MSVC from VSCode 2017 appears unhappy with it (causes an
internal compiler error.)

This also means that we need to avoid doing `sizeof(stubCode)` as
`sizeof(int[N])` on function array parameters decays into `sizeof(int *)`.

Reviewed By: #lld-macho, gkm

Differential Revision: https://reviews.llvm.org/D100605