[lld] [llvm] [LLD][COFF] Prefetch inputs early-on to improve link times (PR #169224)

[Alexandre Ganea via llvm-commits]

aganea wrote:

Also FWIW a summary of the memory usage for the above example: ~13 GB of RAM are allocated by LLD; ~24 GB are memory-mapped inputs; ~3.5 GB are the memory-mapped outputs (PDB and EXE). Overall the working set peaks at about 40.5 GB. For the same thing, `link.exe` peaks at 57 GB.

https://github.com/llvm/llvm-project/pull/169224