Summary:
Print a warning if the wrong cache script is used when generating a Xcode project, because it's too easy to confuse with Apple-lldb-macOS.cmake
```
When building with Xcode, we recommend using the corresponding cache
script. If this was a mistake, clean your build directory and re-run
CMake with:
-C /path/to/llvm-project/lldb/cmake/caches/Apple-lldb-Xcode.cmake
See: https://lldb.llvm.org/resources/build.html#cmakegeneratedxcodeproject
```
Also set the generator inside the cache script.
Reviewers: JDevlieghere, jingham, clayborg
Reviewed By: JDevlieghere
Subscribers: mgorny, lldb-commits, #lldb
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D65797
llvm-svn: 368066
7f34a3652e