Log Message:
mold: update to 1.6.0.

New features:

- [ppc64] mold now supports the original 64-bit big-endian PowerPC ABI
  (which is also known as PPC64 ELFv1 or just ppc64), so that you can
  build applications for older PPC64 systems with mold. Note that this
  should not be confused with the modern PPC64 ELFv2 ABI (which is also
  known as ppc64le), which is already supported by mold.
- [s390x] Linux/s390x is now supported. Linux/s390x is the Linux
  environment on IBM z/Architecture mainframes. I've personally never
  seen a mainframe, but we wanted to support it because many Linux
  distros actively support that target, which in turn means there are
  many enterprise users who are using IBM mainframes. Speaking of the
  porting effort, we do not only port our linker to s390x but also found
  a couple of issues with the existing GCC toolchain for s390x. So, we
  are improving the whole IBM mainframe ecosystem!
- mold now creates smaller output files. It is most noticeable on targets
  with large page sizes such as PPC64 (on which the common page size is
  64 KiB), but even on x86-64, it should save a few kilobytes per an
  output file.

Bug fixes and compatibility improvements:

- [arm64] mold can now link executables with -static-pie. Previously,
  executables linked with that flag crashed immediately.