[lworld] Clean up compiler test cases

[Tobias Hartmann]

Hi Ioi,

On 19.07.2018 07:16, Ioi Lam wrote:
> I found that 7 valhalla tests for the compiler[1] have many very
> long @run command-lines [2].
> 
> The reason for having these @run cases is to test with different VM
> options. However, it's very difficult to maintain, especially when they
> are copied several times and are subsequently modified independently.

Yes, we need all those flag combinations because the compiler has many different optimization paths.
The test also performs pattern matching on the C2 IR for only some of these combinations to catch
performance regressions (see -DVerifyIR= ).

> I wrote a script to analyze the options [3]. If no one objects, I will
> refactor these tests to replace these @run lines with something more
> manageable.

Sure, that would be great. We just have to make sure that we don't reduce coverage.

Thanks,
Tobias