Add stage 06: Lua bootstrap

The goal of stage 06 is to try parse zig synax in lua. I pulled in
lpeglable 1.2.0 and parser-gen off github to get started. All of this
needs to be cleaned up rather soon.

Lua boostraps using tcc and musl from the previous stage. Since musl
0.6.0 doesn't support dynamic linking this build of lua doesn't support
shared libraries. I couldn't easily patch musl with dlopen and friends
so instead I link statically and call deps with c api.

06/parser-gen/parser-gen-tests.lua

@@ -0,0 +1,160 @@
+local pg = require "parser-gen"
+local peg = require "peg-parser"
+local re = require "relabel"
+
+local eq = require "equals"
+
+local equals = eq.equals
+
+
+local pr = peg.print_r
+
+
+-- terminals
+-- space allowed
+rule = pg.compile [[
+rule <-  'a'
+]]
+str = "a   a aa "
+res = pg.parse(str,rule)
+assert(res)
+
+-- space not allowed
+rule = pg.compile [[
+RULE <- 'a' 'b'
+]]
+str = "a     b"
+res = pg.parse(str,rule)
+assert(not res)
+
+-- space not allowed 2
+rule = pg.compile [[
+rule <- 'a' 'b'
+SKIP <- ''
+SYNC <- ''
+]]
+str = "a     b"
+res = pg.parse(str,rule)
+assert(not res)
+
+-- custom space
+rule = pg.compile [[
+rule <- 'a' 'b'
+SKIP <- DOT
+DOT <- '.'
+]]
+str = "a...b"
+res = pg.parse(str,rule)
+assert(res)
+
+-- non terminals
+-- space allowed
+rule = pg.compile [[
+rule <- A B
+A	<- 'a'
+B	<- 'b'
+]]
+str = "a     b"
+res, err = pg.parse(str,rule)
+assert(res)
+-- no spaces allowed
+rule = pg.compile [[
+RULE <- A B
+A	<- 'a'
+B	<- 'b'
+]]
+str = "a     b"
+res = pg.parse(str,rule)
+assert(not res)
+
+-- space in the beginning and end of string
+rule = pg.compile [[
+rule <- A B
+A	<- 'a'
+B	<- 'b'
+]]
+str = "  a     b  "
+res = pg.parse(str,rule)
+assert(res)
+
+
+
+-- TESTING CAPTURES
+
+r = pg.compile([[ rule <- {| {:'a' 'b':}* |} 
+
+				]],_,_,true)
+res = pg.parse("ababab", r)
+
+assert(equals(res,{"ab","ab","ab"}))
+-- space in capture
+
+rule = pg.compile([[ rule <- {| {: 'a' :}* |} 
+]],_,_,true)
+str = " a a a "
+res = pg.parse(str,rule)
+
+assert(equals(res,{"a","a","a"})) -- fails
+
+-- TESTING ERROR LABELS
+local labs = {errName = "Error number 1",errName2 = "Error number 2"}
+pg.setlabels(labs)
+rule = pg.compile [[ rule <- 'a' / %{errName}
+					SYNC <- '' 
+					]]
+local errorcalled = false
+local function err(desc, line, col, sfail, recexp)
+	errorcalled = true
+	assert(desc == "Error number 1")
+end
+res = pg.parse("b",rule,err)
+assert(errorcalled)
+
+-- TESTING ERROR RECOVERY
+
+local labs = {errName = "Error number 1",errName2 = "Error number 2"}
+pg.setlabels(labs)
+
+rule = pg.compile [[ 
+rule <- As //{errName,errName2} Bs
+As <- 'a'* / %{errName2}
+Bs <- 'b'*
+]]
+res1 = pg.parse(" a a a",rule)
+res2 = pg.parse("b b b ",rule)
+assert(res1 and res2)
+
+-- TESTING ERROR GENERATION
+
+pg.setlabels({})
+rule = pg.compile([[
+rule <- A B C 
+A <- 'a'
+B <- 'b'
+C <- 'c'
+
+]],_,true)
+res1, errs = pg.parse("ab",rule)
+assert(errs[1]["msg"] == "Expected C")
+
+-- TESTING RECOVERY GENERATION
+
+
+-- SELF-DESCRIPTION
+pg.setlabels(peg.labels)
+gram = pg.compile(peg.gram, peg.defs,_,true)
+res1, errs = pg.parse(peg.gram,gram)
+assert(res1) -- parse succesful
+
+--[[ this test is invalid since tool added ^LABEL syntax
+r = re.compile(peg.gram,peg.defs)
+res2 = r:match(peg.gram)
+
+--peg.print_r(res2)
+
+assert(equals(res1, res2))
+]]--
+
+
+
+print("all tests succesful")