This breaks all machines because the declared return type void
disagrees with the implicit return type int (when I compile mach.c
with clang). Unbreak i386, i80, i86, m68020, powerpc, vc4 by adding
the return types to mach.c. We don't build any other machines; they
are broken since commit a46ee91 (May 19, 2013) declared void prolog()
and commit fd91851 (Nov 10, 2016) declared void mes(), with both
declarations in mach/proto/ncg/fillem.c.
Also fix mach/vc4/ncg/mach.c where type full is long, so fprintf()
must use "%ld" not "%d" to print full nlocals.
Files that #include "equiv.h" must do so after including "data.h", now
that a function prototype in equiv.h uses type rl_p from data.h.
Adjust style, changing some `for(...)` to `for (...)`. The style in
mach/proto/ncg is less than consistent; the big annoyance now is that
some files want tabs at 4 spaces, others want tabs at 8 spaces.
*Important:* You must "make clean" after checking out this commit,
because the build had copied the old "assert.h" to several places in
obj/. If you don't "make clean", then the compiler finds the old
"assert.h" before libc <assert.h>, and the build fails because this
commit removes badassertion() in subr.c. After "make clean", the
compiler finds libc <assert.h> and the build succeeds.
