cortexmf4: cannot find function `__builtin_arm_set_fpscr` in this scope

When trying to compile the bottles example for any cortexm4_f_:

   Compiling c2rust-bitfields v0.3.0
error[E0425]: cannot find function `__builtin_arm_get_fpscr` in this scope
    --> /home/kaspar/tmp/riot-examples/bottles/target/thumbv7em-none-eabihf/debug/build/riot-sys-1b24665d237c7b4d/out/riot_c2rust_replaced.rs:3045:12
     |
3045 |     return __builtin_arm_get_fpscr() as uint32_t;
     |            ^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope

error[E0425]: cannot find function `__builtin_arm_set_fpscr` in this scope
    --> /home/kaspar/tmp/riot-examples/bottles/target/thumbv7em-none-eabihf/debug/build/riot-sys-1b24665d237c7b4d/out/riot_c2rust_replaced.rs:3092:5
     |
3092 |     __builtin_arm_set_fpscr(fpscr);
     |     ^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0425`.
error: could not compile `riot-sys`

To learn more, run the command again with --verbose.
make: *** [../Makefile.cargo:22: target//debug/libbottles.a] Error 101