When testing on openSUSE Leap 15.4 I ran into this FAIL:
...
FAIL: gdb.arch/i386-mpx-map.exp: NULL address of the pointer
...
and likewise for all the other mpx tests.
The problem is that have_mpx is supposed to return 0, but it doesn't because
it tries to match this output:
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builtin_spawn -ignore SIGHUP temp/20294/have_mpx-2-20294.x^M
No MPX support^M
No MPX support^M
...
using:
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&& ![string equal $output "No MPX support\r\n"]]
...
Fix this by matching using a regexp instead.
Tested on x86_64-linux.
