[TSan] Rename file to make it clear that it defines interceptors

Rename file `tsan_libdispatch.cpp -> tsan_libdispatch_interceptors.cpp`
to make it clear that it's main purpose is defining interceptors.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@369289 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed