Code refactoring is a common need for C developers and availability of eiter automated or semi-automated tools can be really helpful.
Since LabWindows/CVI now uses llvm+clang, probably a tool like "include-what-you-use" can be integrated.
This is the github page for the tool.
From the documentation:
"Include what you use" means this: for every symbol (type, function variable, or macro) that you use in foo.cc, either foo.cc or foo.h should #include a .h file that exports the declaration of that symbol. The include-what-you-use tool is a program that can be built with the clang libraries in order to analyze #includes of source files to find include-what-you-use violations, and suggest fixes for them.
The main goal of include-what-you-use is to remove superfluous #includes. It does this both by figuring out what #includes are not actually needed for this file (for both .cc and .h files), and replacing #includes with forward-declares when possible.
Is this tool available in CVI?
If not, I can open a new suggestion in the Idea Exchange Forum (if CVI is actively developed - I have some doubts 
)