[all-commits] [llvm/llvm-project] abb007: build: reduce CMake handling for zlib

[Saleem Abdulrasool via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: abb00753069554c538f3d850897373d093389945
      https://github.com/llvm/llvm-project/commit/abb00753069554c538f3d850897373d093389945
  Author: Saleem Abdulrasool <compnerd at compnerd.org>
  Date:   2020-01-02 (Thu, 02 Jan 2020)

  Changed paths:
    M clang/test/CMakeLists.txt
    M clang/test/lit.site.cfg.py.in
    M compiler-rt/test/lit.common.configured.in
    M lld/test/CMakeLists.txt
    M lld/test/lit.site.cfg.py.in
    M lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
    M lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
    M llvm/CMakeLists.txt
    M llvm/cmake/config-ix.cmake
    M llvm/include/llvm/Config/config.h.cmake
    M llvm/lib/Support/CMakeLists.txt
    M llvm/lib/Support/CRC.cpp
    M llvm/lib/Support/Compression.cpp
    M llvm/test/CMakeLists.txt
    M llvm/test/lit.site.cfg.py.in
    M llvm/unittests/Support/CompressionTest.cpp

  Log Message:
  -----------
  build: reduce CMake handling for zlib

Rather than handling zlib handling manually, use `find_package` from CMake
to find zlib properly. Use this to normalize the `LLVM_ENABLE_ZLIB`,
`HAVE_ZLIB`, `HAVE_ZLIB_H`. Furthermore, require zlib if `LLVM_ENABLE_ZLIB` is
set to `YES`, which requires the distributor to explicitly select whether
zlib is enabled or not. This simplifies the CMake handling and usage in
the rest of the tooling.

This restores 68a235d07f9e7049c7eb0c8091f37e385327ac28,
e6c7ed6d2164a0659fd9f6ee44f1375d301e3cad.  The problem with the windows
bot is a need for clearing the cache.