different output from gcc for c-testsuite's 00206.c

[samkho]

For https://github.com/c-testsuite/c-testsuite/tree/master/tests/single-exec/00206.c...

gcc outputs:

abort = 111 abort = 222 abort = 333 abort = 222 abort = 111

chibicc outputs:

abort = 111 abort = 222 abort = 333 abort = 333 abort = 333