[compiler-rt] [rtsan] Restrict arches and disable android (PR #98268)

[via llvm-commits]

dyung wrote:

> > If someone has a reproducible way to get it, and can propose a fix we would be eternally grateful!
> > We have yet to see it on our local builds.
> 
> My bot is a fairly standard Ubuntu 20.04 x86_64 machine. Do you have a similarly setup machine? Running the cmake and build commands might work to try and reproduce the issue.

Taking a quick look at my bot, trying to run the unittest binary immediately results in a segfault:
```
~/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/lib/rtsan/tests$ ./Rtsan-x86_64-NoInstTest 
Segmentation fault (core dumped) 
```
This seems to explain why we see this output. From llvm/utils/lit/lit/formats/googletest.py, there is this comment on line 126:
```
                    # This doesn't look like a valid gtest file.  This can
                    # have a number of causes, none of them good.  For
                    # instance, we could have created a broken executable.
                    # Alternatively, someone has cruft in their test
                    # directory.  If we don't return a test here, then no
                    # failures will get reported, so return a dummy test name
                    # so that the failure is reported later.
```

https://github.com/llvm/llvm-project/pull/98268