change default optimization level to O3

[zapashcanon]

No description provided.

[zapashcanon]

cc @filipeom, in test/c/collections-c/pqueue_tests.t we are not detecting the heap overflow with -O3, I don't know these tests so I would say it's a regression but on Test-Comp we're clearly better with -O3 so I'd like to still make it the default, what do you think?

[filipeom]

cc @filipeom, in test/c/collections-c/pqueue_tests.t we are not detecting the heap overflow with -O3, I don't know these tests so I would say it's a regression but on Test-Comp we're clearly better with -O3 so I'd like to still make it the default, what do you think?

I think it's ok, it's expected when one compiles with optimizations some memory errors might no longer be detected. For Test-Comp we're not focused on verifying memory safety so I agree that we should make the best parameters the default 😄