It looks like the fuchsia port relied on inheriting the multilib rules from the bare-metal port (the t-arm-elf makefile fragment), but that has now been rewritten on the assuption that the base architecture is ARMv4t; fuchsia has a base architecture of ARMv7-a.
To account for this, I've cloned the original t-arm-elf rules into a new makefile fragment t-fuchsia and arranged for that to be used when targetting this system.
- config/arm/t-fuchsia: New file.
- config.gcc (arm*-*-fuchsia*): Use it.
ea0d512 [arm] Rework multilib support
gcc/ChangeLog | 5 +++++
gcc/config.gcc | 2 +-
gcc/config/arm/t-fuchsia | 33 +++++++++++++++++++++++++++++++++
3 files changed, 39 insertions(+), 1 deletion(-)