[TSan] Remove legacy Makefile.old!

Summary:
It was barely supported for a several years for now, somewhat
rotten and doesn't correspond to the way we build/test TSan runtime
in Clang anymore.

CMake build has proper compile flags, library layout, build
dependencies etc.

Shell scripts that depended on the output of Makefile.old are
either obsolete now (check_cmake.sh), or moved to lit tests
(check_memcpy.sh), or kept as a standalone scripts not suitable
for generic test suite, but invoked on bots (check_analyze.sh).

It is not used on bots anymore: all "interesting" configurations
(gcc/clang as a host compiler; debug/release build types) are now
tested via CMake.

Reviewers: dvyukov, kcc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15316

llvm-svn: 255032