Bug path

‘test_1’: events 1-3
12 void *ptr = malloc (1024);
^~~~~~~~~~~~~
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(1) allocated here
13 free (ptr);
~~~~~~~~~~
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(2) first ‘free’ here
14 free (ptr); /* { dg-warning "double-'free' of 'ptr'" } */
~~~~~~~~~~
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(3) second ‘free’ here; first ‘free’ was at (2)