Please describe the problem:
$ ./unicode-encoding 
line 24: results of conversion to ucs16 do not match
line 36: results of conversion to ucs16 do not match
line 40: results of conversion to ucs16 do not match
line 44: results of conversion to ucs16 do not match
line 56: results of conversion to ucs16 do not match
line 60: results of conversion to ucs16 do not match
line 82: results of conversion to ucs16 do not match
line 86: results of conversion to ucs16 do not match
line 90: results of conversion to ucs16 do not match
line 94: results of conversion to ucs16 do not match
line 299: results of conversion to ucs16 do not match


If I change the fail line to:
fail ("line %d: results of conversion to ucs16 do not match\n%x vs %x vs %x\n", line, utf16_from_utf8, utf16_expected, utf16_from_ucs4);

I get:
line 24: results of conversion to ucs16 do not match
10016450 vs 100156e0 vs 10016470
line 36: results of conversion to ucs16 do not match
100164d0 vs 100164b0 vs 100164f0
line 40: results of conversion to ucs16 do not match
10016b50 vs 10016510 vs 10016b70
line 44: results of conversion to ucs16 do not match
10016bd0 vs 10016b90 vs 10016bf0
line 56: results of conversion to ucs16 do not match
10016c50 vs 10016c10 vs 10016c70
line 60: results of conversion to ucs16 do not match
10016cd0 vs 10016c90 vs 10016cf0
line 82: results of conversion to ucs16 do not match
10016d50 vs 10016d10 vs 10016d70
line 86: results of conversion to ucs16 do not match
10016dd0 vs 10016d90 vs 10016df0
line 90: results of conversion to ucs16 do not match
10016e50 vs 10016e10 vs 10016e70
line 94: results of conversion to ucs16 do not match
10016ed0 vs 10016e90 vs 10016ef0
line 299: results of conversion to ucs16 do not match
10018c20 vs 10018c00 vs 10018c40


2.16.3 didn't fail this test here and I can't reproduce it on amd64.

Steps to reproduce:
1. 
2. 
3. 


Actual results:


Expected results:


Does this happen every time?


Other information: