Bug#943732: pandas: test fails/crashes on mipsel

[Rebecca N. Palmer]

Control: retitle -1 pandas: test fails/crashes on mipsel

arm* = new tests hitting the already-known issue #877754
(which I don't like having open with no user-level warning, but blocking 
the transition over it doesn't actually help)
s390x/ppc64 = bug in the tests, not the library
riscv64 = looks NaN-handling-related, possibly in numpy (their 
TestBoolCmp.test_float fails as well, but doesn't fail the build due to 
#943369), not a release arch

This leaves mipsel as the only RC issue: ~100 failures (many, but not 
all, xz compression related), an intermittent crash, and no detailed 
output because of a MemoryError while trying to print it(!).