RFR: merge of 8203197

[Roman Kennke]

Arg, damn. Resolve as below, should be easy:

> There are a couple of non c2 files with conflicts:
> 
>   # All variants but minimal (and custom) get these features
> <<<<<<< local
>   NON_MINIMAL_FEATURES="$NON_MINIMAL_FEATURES cmsgc g1gc parallelgc serialgc epsilongc shenandoahgc jni-check jvmti management nmt services vm-structs"
> =======
>   NON_MINIMAL_FEATURES="$NON_MINIMAL_FEATURES cmsgc g1gc parallelgc serialgc epsilongc jni-check jvmti management nmt services vm-structs"
> 
>   AC_MSG_CHECKING([if cds should be enabled])
>>>>>>>> other

Take:

  NON_MINIMAL_FEATURES="$NON_MINIMAL_FEATURES cmsgc g1gc parallelgc
serialgc epsilongc shenandoahgc jni-check jvmti management nmt services
vm-structs"

  AC_MSG_CHECKING([if cds should be enabled])

(i.e. the 'other' block with shenandoahgc inserted)

> 
> void GCConfig::select_gc_ergonomically() {
>   if (os::is_server_class_machine()) {
> #if INCLUDE_G1GC
>     FLAG_SET_ERGO_IF_DEFAULT(bool, UseG1GC, true);
> #elif INCLUDE_PARALLELGC
>     FLAG_SET_ERGO_IF_DEFAULT(bool, UseParallelGC, true);
> #elif INCLUDE_SERIALGC
>     FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true);
> #endif
>   } else {
> #if INCLUDE_SERIALGC
>     FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true);
> #endif
>   }
> <<<<<<< local
> 
>   NOT_CMSGC(     UNSUPPORTED_OPTION(UseConcMarkSweepGC));
>   NOT_EPSILONGC( UNSUPPORTED_OPTION(UseEpsilonGC);)
>   NOT_G1GC(      UNSUPPORTED_OPTION(UseG1GC);)
>   NOT_PARALLELGC(UNSUPPORTED_OPTION(UseParallelGC);)
>   NOT_PARALLELGC(UNSUPPORTED_OPTION(UseParallelOldGC));
>   NOT_SERIALGC(  UNSUPPORTED_OPTION(UseSerialGC);)
>   NOT_ZGC(       UNSUPPORTED_OPTION(UseZGC);)
>   NOT_SHENANDOAHGC(UNSUPPORTED_OPTION(UseShenandoahGC));
> =======
>>>>>>>> other

> }
> 
> in src/hotspot/share/gc/shared/gcConfig.cpp

Simply remove the block, e.g. as in 'other'.

I hope that works.

Thanks,
Roman