[KernelAddressSanitizer] Fix globals exclusion for indirect aliases
    
    GlobalAlias::getAliasee() may not always point directly to a
    GlobalVariable. In such cases, try to find the canonical GlobalVariable
    that the alias refers to.
    
    Link: https://github.com/ClangBuiltLinux/linux/issues/1208
    
    Reviewed By: dvyukov, nickdesaulniers
    
    Differential Revision: https://reviews.llvm.org/D92846
    
    (cherry picked from commit c28b18af19621e6b5cca257ef7139ba93833df0c)