The HAVE_LIBZ variable is not exported by LLVM, and therefore is not
available in stand-alone builds of other tools. Use LLVM_ENABLE_ZLIB
which is the name under which the effective value is exported.
Additional, use llvm_canonicalize_cmake_booleans() to make sure that
a correct (Python-safe) boolean value is passed down to lit.
Differential Revision: https://reviews.llvm.org/D41725
llvm-svn: 322081
c5e0b63e56