[clang] [compiler-rt] [Driver] [compiler-rt] Move sanitizer ignorelists from compiler-rt to clang (PR #195396)

[Andrew Haberlandt via cfe-commits]

ndrewh wrote:

> E.g. sanitizers .a and .h files also go into shared resource dir, but it does not mean they need to be in clang source tree.

The compiler instrumentation (and the associated ignore-lists) can be used without any runtime support from compiler-rt (e.g. UBSan trap mode, or third-party runtimes). I'm not sure if there's a use-case for the headers or `.a` files without having runtime support.

> just wondering if this makes enough difference dealing with breackages.

Is the breakage concern about the ignorelists no longer being installed by standalone compiler-rt builds? For a "typical" `LLVM_ENABLE_RUNTIMES` install, I wouldn't have expected anyone to notice the change.

That said, I've split this into two PRs. The first (#195690) adds the `CLANG_ENABLE_SANITIZER_SYSTEM_IGNORELISTS_DEFAULT` option to enable/disable the inclusion of system ignorelists in the driver, and disables this by default on Darwin.

This PR (#195396) now "just" moves the ignorelists from compiler-rt to clang and can be considered separately.

https://github.com/llvm/llvm-project/pull/195396