[CMake] Bug 23468 - LLVM_OPTIMIZED_TABLEGEN does not work with Visual Studio

Summary: Multi-configuration builds put their binaries into ${CMAKE_BINARY_DIR}/Release/bin/. The table-gen cross-compilation support needs to take that into account.

Reviewers: yaron.keren

Reviewed By: yaron.keren

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10102

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238592 91177308-0d34-0410-b5e6-96231b3b80d8