The unittest .o files also depend on some of the llvm2ice headers, as well as the unittest headers.

To reproduce the problem, try this:

make -f Makefile.standalone clean
make -f Makefile.standalone check-unit 2>/dev/null | grep BitcodeMunge.cpp

This will print a line containing BitcodeMunge.cpp.

Now do:

touch unittest/BitcodeMunge.h
make -f Makefile.standalone check-unit 2>/dev/null | grep BitcodeMunge.cpp

This should print a line, but it doesn't.

Finally:

touch src/PNaClTranslator.h
make -f Makefile.standalone check-unit 2>/dev/null | grep BitcodeMunge.cpp

This should also print a line, but it doesn't.

With this patch, the unittest files get rebuilt after header file changes.

BUG= none
R=jvoung@chromium.org, kschimpf@google.com

Review URL: https://codereview.chromium.org/895143003