depcomp on system headers

[David Everly]

The automake documentation...

http://www.gnu.org/software/automake/manual/html_mono/automake.html#Dependencies

...indicates:

"Automake always uses complete dependencies for a compilation,
including system headers."

However, a closed-source vendor gives us header files that contain:

#include <numbrw.cc>

This means that after I finish compiling, when I run make a second
time it tries to compile
/opt/aCC/include_std/rw/numbrw.cc, and of course, gets an error.

I've modified depcomp so that it uses "+maked" instead of "+Maked"
(aCC compiler option) documented here:

     +Make[d]       Same as +make[d] except both <> and "" enclosed include
                    files are output as dependencies.

     +make[d]       This option outputs the double quoted ("") enclosed
                    include file dependency information

However, is there a better way to respond to this problem?  Perhaps
some automake option I've forgotten?  I've already opened a bug
against the vendor.