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/equals.lua

@@ -0,0 +1,32 @@
+-- this function compares if two tables are equal
+local function equals(o1, o2, ignore_mt)
+    if o1 == o2 then return true end
+    local o1Type = type(o1)
+    local o2Type = type(o2)
+    if o1Type ~= o2Type then return false end
+    if o1Type ~= 'table' then return false end
+
+    if not ignore_mt then
+        local mt1 = getmetatable(o1)
+        if mt1 and mt1.__eq then
+            --compare using built in method
+            return o1 == o2
+        end
+    end
+
+    local keySet = {}
+
+    for key1, value1 in pairs(o1) do
+        local value2 = o2[key1]
+        if value2 == nil or equals(value1, value2, ignore_mt) == false then
+            return false
+        end
+        keySet[key1] = true
+    end
+
+    for key2, _ in pairs(o2) do
+        if not keySet[key2] then return false end
+    end
+    return true
+end
+return {equals=equals}