dlopen() fixes (#929)

* 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.

lpl_ca/lpl.hpp

@@ -4,7 +4,7 @@
 
 #include "clara/clara.hpp"
 #include "pstreams/pstream.h"
-#include "../src/elfio/elfio.hpp"
+#include "../include/hip/hcc_detail/elfio/elfio.hpp"
 
 #include <unistd.h>