heap corruption in read_csv on 32-bit big-endian architectures

[ginggs]

While building pandas 0.22.0 for 32-bit big-endian architectures, the test suite crashes in TestMultiLevel::test_unstack_odd_failure with various errors:

realloc(): invalid next size
malloc(): smallbin double linked list corrupted
Segmentation fault
corrupted double-linked list

This happened to be the first test that calls read_csv, and I could reproduce this in the REPL by simply doing:

import pandas as pd
df = pd.read_csv('data.csv')

I narrowed it down to 8d7d3fb and found #17063 describing a similar problem introduced by the same commit affecting other 32-bit architectures.

[jreback]

you could submit a patch, but we have 0 support for big endian (no testing) and very little for 32-but arch (limited testing)