When the compiler times out, retry without -O2.
When the compiler times out, retry without -O2.

Fixes #645.

pranjaltale16/codeworld,alphalambda/codeworld,pranjaltale16/codeworld,pranjaltale16/codeworld,google/codeworld,google/codeworld,alphalambda/codeworld,alphalambda/codeworld,google/codeworld