[compiler-rt] [compiler-rt][rtsan] Introduce first end to end RTsan lit tests, enable instrumented unit tests (PR #105732)

[Chris Apple via llvm-commits]

cjappl wrote:

> Please fix these warnings, or some bots will fail:
> 
> rtsan_test_functional.cpp:159:44: warning: unused variable 'x' rtsan_test_functional.cpp:163:28: warning: unused variable 'x'
> 
> gtest.h:1379:11: warning: comparison of integers of different signs from rtsan_test_functional.cpp:148:5:
> 
> rtsan_test_interceptors.cpp:325:59: warning: variable 'thread_info' is uninitialized when used here

Thank you for catching these @vitalybuka! That saved me a lot of headache. 

Did you pull these warnings from somewhere specific, or just building on your own machine? I want to know so I can catch these before I put up any future reviews, and I don't see them on my local mac or ubuntu builds (or the build machine logs)

https://github.com/llvm/llvm-project/pull/105732