consolidate thread local storage (#915)

* 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


[ROCm/hip commit: 1eb3dbf065]

projects/hip/src/hip_clang.cpp

@@ -177,6 +177,7 @@ hipError_t hipConfigureCall(
   size_t sharedMem,
   hipStream_t stream)
 {
+  GET_TLS();
   auto ctx = ihipGetTlsDefaultCtx();
   LockedAccessor_CtxCrit_t crit(ctx->criticalData());