Building clang encounters llvm samples.c problem

I am building clang on Mingw in Windows. I was able to straighten out an earlier problem and now everything in clang appears to build correctly.

Near the end of "make" processing, it seems, I eventually ran into this error:

"llvm[4]: Compiling sample.c for Debug+Asserts build

fatal error: sample.h: No such file or directory
compilation terminated."

Looking at sample.c I see:

#include "sample.h"

but there is no sample.h in the same directory as sample.c but only in
the llvm/projects/sample/include directory.

Is this an LLVM problem or is it related to clang in some way ? Should not it be '#include <sample.h>' instead ? Has clang completely finished building once this occurs ?

It does look like everything else built OK and the error is only
occuring trying to build the sample program for LLVM.