The new option is `linker` and lets the user specify the argument to
the`-fuse_ld=` linker flag directly. The supported options are:
- `default`: No change, typically uses GNU ld (bfd) unless the user or
distro picked a different default `/usr/bin/ld`.
- `bfd`: GNU ld from binutils
- `gold`: GNU gold from binutils
- `lld`: lld from LLVM
- `mold`: mold, an extremely fast modern linker, not (yet) intended for
use in production but great for development speed. Provided by distro
`mold` package or needs to be compiled from source and installed to
`/usr` otherwise.
Deprecates the `use_lld=yes` option, and make lld actually usable with
GCC too.
Not all the above are compatible or recommend for LTO, we recommend
using GNU ld with GCC LTO, or lld with LLVM ThinLTO.
(cherry picked from commit 534f85add1daec0669a1f18edd2cc456f9a296ef)
5bb3063eec