Bug introduced #120995. The LLD code calculates the "size" of the Mach-O
headers, and then uses that size to place the segments, but the `__TEXT`
section stays at `fileoff` zero. When I wrote the code into llvm-objcopy
I calculated the extra space into the initial offset, which moved all
the sections back 1 page.
Besides the modified test checking for the right `fileoff` values of the
sections and the segments, I also manually checked the generated
binaries after `llvm-objcopy` using `dyld_info`, as the bug report
suggested.
Fixes#130472
(cherry picked from commit 8413f4d837a96458104f63bab72c751b8285a458)
cb50aaf8a1