Segfault/invalid stdio handle/double free or corruption (!prev)

[jajhall]

In

https://github.com/rust-or/highs/issues/3#

it's suggested that "there may be a double-free when a problem is created with Highs_create, then incoherent values are passed with Highs_passLp, which returns an error status, and then the problem is freed with Highs_destroy. I added a fuzzer which found that issue almost immediately. It may be pertinent for you to add fuzzing directly to HiGHS."

"Looking into it deeper, it looks like the problem (or at least one problem) comes from the fclose(log_file_stream) in Highs' destructor. HiGHS may be trying to close an already closed file."