`fatal` should only be used for malformed inputs according to
ErrorHandler.h; `error` is more appropriate for missing arguments,
accompanied by a check to bail out early in case of the error. Some
tests need to be adjusted accordingly.
Makes `lld/test/MachO/arch.s` pass with `LLD_IN_TEST=2`.
Reviewed By: #lld-macho, int3
Differential Revision: https://reviews.llvm.org/D112879
D93491 implemented `--version` for the MachO LLD port, but asserts that the string contains something like "LLD N.N". However, this is just the cmake default for `LLD_VERSION_STRING`, and downstream users may choose a different value, e.g. a rolling distro may print "LLD trunk".
It's an extension to ld64, but all the other ports have it, and
someone asked for it in PR43721.
While here, change the COFF help text to match the other ports.
Differential Revision: https://reviews.llvm.org/D93491
Also use "unknown flag 'flag'" instead of "unknown flag: flag" for
consistency with the other ports.
Differential Revision: https://reviews.llvm.org/D91970
