Parallel check fails

[Andreas Enge]

Hello,

with gmp-6.1.0, "make -j 4 check" fails on two different architectures (armhf
with 4 cores, x86_64 with 2 hyperthreaded cores) with the folowing message:
make[4]: *** No rule to make target '../libgmp.la', needed by 't-bswap'.  Stop.
make[4]: *** Waiting for unfinished jobs....
right at the beginning of the compilation. Otherwise said, the test programs
are compiled in parallel with the library.

I am using GNU make 4.1.

When running "make -j 4" followed by "make -j 4 check", all tests pass on
my x86_64 machine, and the mpz/reuse test fails on my arm machine.

Andreas