[lld-macho] Add LOH_ARM64_ADRP_ADD_LDR optimization hint support

This hint instructs the linker to optimize an adrp+add+ldr sequence used
for loading from a local symbol's address by loading directly if it's
close enough, or with an adrp(p)+ldr sequence if it's not.

This transformation is the same as what's done for ADRP_LDR_GOT_LDR when
the symbol is local. The logic for acting on this hint is therefore
moved to a new function which will be called from the existing
applyAdrpLdrGotLdr() function.

Differential Revision: https://reviews.llvm.org/D130505