Add missing header for _LIBUNWIND_LOG().


git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@211775 91177308-0d34-0410-b5e6-96231b3b80d8
Fix linux build.

* Replace strlcpy with snprintf since strlcpy is not available
  in glibc.

* Replace __LINUX__ with __linux__.



git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@211784 91177308-0d34-0410-b5e6-96231b3b80d8
Silence various unused variable and parameter warnings.
Silence the implicit signed/unsigned conversion warning.
Revert the lsda change to scan_eh_tab.