Add flua to the base system, install to /usr/libexec

[kevans]

Summary

FreeBSDlua ("flua") is a FreeBSD-private lua, flavored with whatever extensions we need for base system operations. We currently support a subset of lfs and lposix that will be used in a rewrite of makesyscall.sh into lua.

flua is intentionally written such that one can install standard lua and some set of lua modules from ports and achieve the same effect.

linit_flua is a copy of linit.c from contrib/lua with lfs and lposix added in. This is similar to what we do in stand/. linit.c has been renamed to make it clear that this has flua-specific bits.

luaconf has been slightly obfuscated to make extensions more difficult. Part of the problem is that flua is already hard enough to use as a bootstrap tool because it's not in PATH- attempting to do extension loading would require a special bootstrap version of flua with paths changed to protect the innocent.

src.lua.mk has been added to make it easy for in-tree stuff to find flua, whether it's bootstrap-flua or relying on PATH frobbing by Makefile.inc1.

[brooks]

Works for me.

[emaste]

go for it!

[imp]

I don't like the lfs.h sharing detail, but it's fine enough we can work out after commit.

[kevans]

Instead of hacking around difficulty in including lfs.h from libexec/flua due to conflicting luaconf.h, -include it in via CFLAGS and remove the prototype entirely from interp_lua.c

[imp]

If you moved lfs.[ch] to libexec/flua/modules, then a simple -I addition to CFLAGS and a .PATH would get the job done.

[kevans]

Split out lfs/lposix to libexec/flua/modules

[imp]

libexec/flua/modules/lfs.c

57 ↗

(On Diff #64427)

stray blank line..

347 ↗

(On Diff #64427)

I'd be tempted to break the line between S_IXGRP and S_IROTH

libexec/flua/modules/lposix.c

3 ↗

(On Diff #64427)

consider not including this phrase.

[kevans]

Address further review comments from @imp