[NFC][TSan][libdispatch] Rename tsan_block_context_t -> block_context_t
'tsan_' part of the struct name is redundant since we are already inside
the __tsan namespace.
llvm-svn: 355539
This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments.