Revert 316150 which reinstated r316025.

It fails on some bots and now we know how to reproduce it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316153 91177308-0d34-0410-b5e6-96231b3b80d8

cmake/config-ix.cmake

@@ -132,17 +132,7 @@ endif()
 # like strlen, leading to false positives.
 if( NOT PURE_WINDOWS AND NOT LLVM_USE_SANITIZER MATCHES "Memory.*")
   if (LLVM_ENABLE_ZLIB)
-    find_package(ZLIB)
-    if (ZLIB_FOUND)
-      set(HAVE_LIBZ 1)
-    else()
-      # Some LLVM bots do not have zlib in a standard location and rely on the
-      # compiler to find it.
-      check_library_exists(z compress2 "" HAVE_LIBZ)
-      if(HAVE_LIBZ)
-        set(ZLIB_LIBRARIES z)
-      endif()
-    endif()
+    check_library_exists(z compress2 "" HAVE_LIBZ)
   else()
     set(HAVE_LIBZ 0)
   endif()

lib/Support/CMakeLists.txt

@@ -22,7 +22,7 @@ elseif( CMAKE_HOST_UNIX )
   endif()
   set(system_libs ${system_libs} ${LLVM_PTHREAD_LIB})
   if ( LLVM_ENABLE_ZLIB AND HAVE_LIBZ )
-    set(system_libs ${system_libs} ${ZLIB_LIBRARIES})
+    set(system_libs ${system_libs} z)
   endif()
   if( UNIX AND NOT (BEOS OR HAIKU) )
     set(system_libs ${system_libs} m)