Currently we see regular failures with:

• The quick-start checks
• An OpenMP test that runs after the "big mmap" test

This OpenMP failure could either be due to the mmap test beforehand not clearing up properly (it allocates >1GB of wasm memory), or something to do with the OpenMP test itself.

Changes:

• Temporarily skip SGX tests (using catch2 [.] tag).
• Temporarily disable the "big mmap" test to see if this improves things.
• Remove WAMR codegen nuking (we should have replenished the cache by now).
• Add retry on quick-start test.
• Add crash handler on main tests (to give more info on segfaults).
• Improve the microbench_runner which I used to stress test the OpenMP function.
• Throw an exception is WAVM GC fails as this could cause memory leaks (and was previously only covered by an assert).