[CMake] Unconditionally add .h and .td files to target sources

Previously adding header and table gen files was conditional on using an IDE. Since these files have the `HEADER_FILE_ONLY` attribute applied they are ignored as sources by all non-IDE generators, so there is really no reason not to include them.

Additionally having the CMake always include these files allows the CMake-server to include them in the sources list for targets, which is valuable to anyone using CMake-server integrated tools.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344218 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed