* add default visibility to most APIs in program_state
* remove unwanted C++ headers
* Add symbol visibility pragmas and compiler flags
* Add visibility attribute to APIs in channel_descriptor and hip_hcc
* remove unused headers
* simplify build flags with hcc
* add pragma visibility hidden to functional_grid_launch
* [CMake] add gfx908 back
* all thread local access now through single struct
* clean up old commented-out code, more use of GET_TLS()
* fewer calls to GET_TLS by passing tls as a funtion argument
* revert unnecessary change to printf
* fix failing tests due to TLS change
* fix merge conflicts in ihipOccupancyMaxActiveBlocksPerMultiprocessor
* Initial attempt to switch over to internally linked state.
* Add missing CMake update.
* hipLaunchKernelGGLImpl must be inline as well. Ensure internal linkage.
* Ensure global retrieval uses internally linked state.
* Hide HC in the implementation. Minimise ADL woes.
* Strange software exists, and must be catered to.
* Use a less spammy mechanism for ensuring internal linkage / non-export.
* Remove leftover internal detail.
Siu Chi Chan
Jeff Daily
Alex Voicu
Wen-Heng (Jack) Chung