Symbols beginning with system-specific local label prefixes, typically
.L for ELF systems or L for traditional a.out systems, are
called local symbols. See Symbol Names. Normally you do not see
such symbols when debugging, because they are intended for the use of
programs (like compilers) that compose assembler programs, not for your
notice. Normally both as and ld discard
such symbols, so you do not normally debug with them.
This option tells as to retain those local symbols
in the object file. Usually if you do this you also tell the linker
ld to preserve those symbols.