Fix graphics/Drawfile ahead of CMake 3.11.

The order in which files are placed in mocs_compilation.cpp has changed
in CMake 3.11 compared to CMake 3.10. This shows up places where not all
of the includes needed for a bit of code, are included -- because by chance,
everywhere else they are already included by the time the compiler gets to
the offending header. In switching the order around, compiles fail.

The error message is in the patch -- just a missing type declaration.

Approved by: tcberner (mentor, implicit)
Differential Revision: https://reviews.freebsd.org/D14770