Update countTrailingZeros function usage to match llvm's r182667.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@182683 91177308-0d34-0410-b5e6-96231b3b80d8
lldbPluginOSDarwinKernel doesn't exist.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@182687 91177308-0d34-0410-b5e6-96231b3b80d8