[clang] [compiler-rt] [safestack] Support statically linked executables (PR #190126)

[Vitaly Buka via cfe-commits]

vitalybuka wrote:

@MaskRay we don't support static linking with other sanitizers because interceptors and dlsym do not work.
Is this safe stack work around is reasonable? Should we consider it for others?

https://github.com/llvm/llvm-project/pull/190126