The compiler flags -Wmissing-prototypes and -Wstrict-prototypes generally help
to write code with proper prototypes. This way one can avoid some ugly bugs
because it helps to identify functions that do not have prototypes in headers.
It also helps to improve performance since local functions then have to be
declared "static", so the compiler can do better optimizations.
Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>