[llvm] Make split-file an utility instead of tool

[zero9178]

Summary

split-file is essentially a development tool used for writing tests. Other related tooling for this purpose such as FileCheck, count, not and more are already created via add_llvm_utility instead of add_llvm_tool. The later is more meant as LLVM tools used as part of a toolchain (eg. llvm-ar), not for tools for the development of LLVM itself.

The main semantic difference this makes is that split-file is now built and installed via the LLVM_INSTALL_UTILS and LLVM_BUILD_UTILS instead of LLVM_BUILD_TOOLS and LLVM_INSTALL_TOOLS cmake flags. That way one can use LLVM_BUILD_TOOLS=OFF LLVM_INSTALL_UTILS=ON and have split-file installed along side the other testing tools.

[MaskRay]

Thanks for the explanation. It makes sense to group split-file into not/FileCheck/yaml2obj/count/...

I'd use a [CMake] tag. As of [llvm], keeping it is optional: personally I think the information isn't significant enough to be part of the subject.

[thakis]

Should it move from llvm/tools to llvm/utils then?

[zero9178]

In D130977#3717112, @thakis wrote:

Should it move from llvm/tools to llvm/utils then?

That is probably a good idea. obj2yaml as well as yaml2obj are also utilities using add_llvm_utility which should probably be moved. I'll post a review shortly.

[thakis]

(at D131713)

llvm/tools/split-file/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   Support
   )
 
-add_llvm_tool(split-file
+add_llvm_utility(split-file
   split-file.cpp
   )