Revert "Turn on LLVM_ENABLE_PLUGINS by default on Windows"

This reverts r260262, it broke some LLVM tests (bugpoint).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260339 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed