It (introduced by 556d713c70) appears to be
related to the removed dragonegg project. In addition, the feature was a bit
misnamed and may lur users to unnecessarily use it.
If include files are used in the CUDA preprocessor tests it will cause a
failure due to a missing header file in hosts that do not match the triple
in the test. E.g. powerpc64le have CUDA support but the include files
cannot be used for an x86 target.
llvm-svn: 259769
Fangrui Song