Edit build.lua for programs losing their private assert.h, so they
depend on a list of .h files excluding assert.h.
Remove modules/src/assert; it would be a dependency of cpp.ansi but we
didn't build it, so cpp.ansi uses the libc assert.
I hope that libc <assert.h> can better report failed assertions. Some
old "assert.h" files didn't report the expression. Some reported a
literal "x", because traditional C expanded the macro parameter x in
"x", but ANSI C89 doesn't expand macro parameters in string literals.
Hosts with sizeof(arith) == sizeof(long) == 8 need to set full_mask[1]
through full_mask[8]. Because MAXSIZE == 8, we only had full_mask[0]
through full_mask[7]. This fix declares arith full_mask[MAXSIZE + 1]
and prevents a fatal error: "array full_mask too small for this machine"
