[PATCH] D20466: [MC/ELF] - Fixed incorrect compression.s test

[George Rimar via llvm-commits]

>This does two things:
>
>* Change dwarfdump to print a section that is actually compressed, that is good.
>* Change the CHECK patters to check the full content of the sections.
>I am not sure why you are doing that.
>
>Cheers,
>Rafael

Since test is about compression, I am pretty sure it is a good idea to check the full content of the sections here
That potentially can help to catch here:

1) Algoritm change. If zlib library we are using be changed or becomes corrupted, the check of content would show that instantly.
That a not great chance for that, but probably we might want to know about that.
2) More real case, I guess: currently zlib-gnu style used in this test consists from 'zlib' magic and uncompressed size
of data in big endian format. So at least we want to check that. But check of first 2 fileds are not always safe.
What if some code changes on llvm side will corrupt the content in some random way ?

Main what I want to say is since that is special test directly about compression - it would be good I believe to check as much as possible cases, 
that of course would be excessive for others not directly related tests.

George.