Add compressedrefs support on OSX in OpenJ9

[babsingh]

i) Add compressedrefs support in OMR OSX configure file

If build spec is osx_x86-64_cmprssptrs, then the following three flags
need to be enabled:

1. OMR_GC_COMPRESSED_POINTERS
2. OMR_INTERP_COMPRESSED_OBJECT_HEADER
3. OMR_INTERP_SMALL_MONITOR_SLOT

The above flags were derived using the OMR Linux x86 configure file:
configure_linux_x86.mk.

ii) Add OSX compressedrefs buildspec

1. linux_x86-64.spec and linux_x86-64_cmprssptrs.spec were diff'ed. This
   showed the new fields which were present in the compressedrefs spec.
   Also, it showed the fields which should be removed from the
   compressedrefs spec.

2. osx_x86-64.spec was copied to create osx_x86-64_cmprssptrs.spec.

3. Diff information from 1) was used to update
   osx_x86-64_cmprssptrs.spec.

4. A lot of property names in osx_x86-64*.spec still contain linux
   specific terms such as xa, linux, etc. Such property names are unused in
   OpenJ9 builds. They are retained with incorrect naming to avoid missing
   dependency issues in internal builds. The naming will be fixed at a
   later point if needed.

5. In the osx_x86-64_cmprssptrs.spec, "build_openj9", "build_openj9JDK8"
   and "graph_enableModularityTesting" flags were added; "env_data64",
   "graph_includeThrstatetest", "module_ddr_gdb_plugin" and "module_ddrext"
   flags were removed.

6. For osx_x86-64_cmprssptrs.spec, feature "cmprssptrs" was added and
   feature "crypto" was removed.

Signed-off-by: Babneet Singh sbabneet@ca.ibm.com

[babsingh]

fyi - @DanHeidinga. Related to #36 and ibmruntimes/openj9-openjdk-jdk9#179.

Building locally to verify if compressedrefs SDK is properly generated on OSX.

[babsingh]

fyi @charliegracie @dmitripivkine Getting the following GC error when building a compressedrefs SDK on OSX:

JVMJ9VM015W Initialization error for library j9gc29(2): Failed to instantiate compressed references metadata; 200M requested
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

[dmitripivkine]

this error message means Suballocator can not be initialized properly, most likely can not get memory below 4G: omrmem_ensure_capacity32() returns OMRPORT_ENSURE_CAPACITY_FAILED

[babsingh]

@dmitripivkine does this mean compressedrefs is unsupported on OSX? is it possible to resolve the GC error?

[dmitripivkine]

Would you please check is OMR_PORT_CAN_RESERVE_SPECIFIC_ADDRESS defined?

[babsingh]

yes, OMR_PORT_CAN_RESERVE_SPECIFIC_ADDRESS is defined. OMR OSX related flags are here: configure_osx.mk.

[dmitripivkine]

This is a problem with Port Library Memory Allocation. I hope something is missed there and problem is not fatal. It should be investigated

[babsingh]

fyi - @nbhuiyan @0xdaryl @pshipton

[charliegracie]

There is an issue at OMR for the portlibrary issue. eclipse-omr/omr#15

[DanHeidinga]

@babsingh Checkout https://stackoverflow.com/questions/46916112/osx-ld-why-does-pagezero-size-default-to-4gb-on-64b-osx

[DanHeidinga]

issue #36

[DanHeidinga]

lgtm

[DanHeidinga]

Merging without PR build as mac isn't supported in the PR builds yet