RFR: 8171853: Remove Shark compiler

[Roman Kennke]

Hi David,

thanks for reviewing!

>
> One observation in src/hotspot/cpu/zero/sharedRuntime_zero.cpp, these 
> includes would seem to be impossible:
>
>   38 #ifdef COMPILER1
>   39 #include "c1/c1_Runtime1.hpp"
>   40 #endif
>   41 #ifdef COMPILER2
>   42 #include "opto/runtime.hpp"
>   43 #endif
>
> no?

I have no idea. It is at least theoretically possible to have a platform 
with C1 and/or C2 support based on the Zero interpreter? I'm leaving 
that in for now as it was pre-existing and not related to Shark removal, ok?

>
> In src/hotspot/share/ci/ciEnv.cpp you can just delete the comment 
> entirely as it's obviously C2:
>
> if (is_c2_compile(comp_level)) { // C2
>
> Ditto in src/hotspot/share/compiler/compileBroker.cpp
>
> !     // C2
>       make_thread(name_buffer, _c2_compile_queue, counters, 
> _compilers[1], compiler_thread, CHECK);

Ok, right. For consistency, I also remove // C1 in ciEnv.cpp similarily 
obvious is_c1_compile() call :-)

New webrev:

http://cr.openjdk.java.net/~rkennke/8171853/webrev.02/ 
<http://cr.openjdk.java.net/%7Erkennke/8171853/webrev.02/>

Roman