Lua Generator using IR. (#6940)

* initial hack to get new Lua generator into flatc

* Starting to output enum defs for Lua

* Continue to work on table generation for Lua

* Finished basic getter access for Lua

* Added ability to get object by index

* Finished struct builder

* aliased reflection to r

* finish table builder generation

* register requiring files

* better generated header info

* Tying up loose ends

* Updated reflection to handle struct padding

* Addd type sizes to reflection

* Fixed some vector indirect issues

* Lua tests passed

* Misc cleanup

* ci fixes 1

* ci fixes 2

* renaming

* up size of type sizes

* manually ran clang-format-11 -i src/idl_parser.cpp

* fixed some windows casting

* remove stupid auto import

* more static_casting

* remove std

* update other build environments

* remove scoped enums

* replaced std::to_string with NumToString

* more win fixes

* more win fixes

* replaced old lua with new

* removed auto import

* review responses

* more style fixes

* refactor bfbs_gen_len to use code +=

* added consts

* fix lambda capture for windows

* remove unused return type

tests/MyGame/Example/StructOfStructs.lua

@@ -1,45 +1,58 @@
--- automatically generated by the FlatBuffers compiler, do not modify
+--[[ MyGame.Example.StructOfStructs
 
--- namespace: Example
+  Automatically generated by the FlatBuffers compiler, do not modify.
+  Or modify. I'm a message, not a cop.
+
+  flatc version: 2.0.0
+
+  Declared by  : //monster_test.fbs
+  Rooting type : MyGame.Example.Monster (//monster_test.fbs)
+
+--]]
 
 local flatbuffers = require('flatbuffers')
 
-local StructOfStructs = {} -- the module
-local StructOfStructs_mt = {} -- the class metatable
+local StructOfStructs = {}
+local mt = {}
 
 function StructOfStructs.New()
-    local o = {}
-    setmetatable(o, {__index = StructOfStructs_mt})
-    return o
-end
-function StructOfStructs_mt:Init(buf, pos)
-    self.view = flatbuffers.view.New(buf, pos)
-end
-function StructOfStructs_mt:A(obj)
-    obj:Init(self.view.bytes, self.view.pos + 0)
-    return obj
-end
-function StructOfStructs_mt:B(obj)
-    obj:Init(self.view.bytes, self.view.pos + 8)
-    return obj
-end
-function StructOfStructs_mt:C(obj)
-    obj:Init(self.view.bytes, self.view.pos + 12)
-    return obj
-end
-function StructOfStructs.CreateStructOfStructs(builder, a_id, a_distance, b_a, b_b, c_id, c_distance)
-    builder:Prep(4, 20)
-    builder:Prep(4, 8)
-    builder:PrependUint32(c_distance)
-    builder:PrependUint32(c_id)
-    builder:Prep(2, 4)
-    builder:Pad(1)
-    builder:PrependInt8(b_b)
-    builder:PrependInt16(b_a)
-    builder:Prep(4, 8)
-    builder:PrependUint32(a_distance)
-    builder:PrependUint32(a_id)
-    return builder:Offset()
+  local o = {}
+  setmetatable(o, {__index = mt})
+  return o
 end
 
-return StructOfStructs -- return the module
+function mt:Init(buf, pos)
+  self.view = flatbuffers.view.New(buf, pos)
+end
+
+function mt:A(obj)
+  obj:Init(self.view.bytes, self.view.pos + 0)
+  return obj
+end
+
+function mt:B(obj)
+  obj:Init(self.view.bytes, self.view.pos + 8)
+  return obj
+end
+
+function mt:C(obj)
+  obj:Init(self.view.bytes, self.view.pos + 12)
+  return obj
+end
+
+function StructOfStructs.CreateStructOfStructs(builder, a_id, a_distance, b_a, b_b, c_id, c_distance)
+  builder:Prep(4, 20)
+  builder:Prep(4, 8)
+  builder:PrependUint32(c_distance)
+  builder:PrependUint32(c_id)
+  builder:Prep(2, 4)
+  builder:Pad(1)
+  builder:PrependInt8(b_b)
+  builder:PrependInt16(b_a)
+  builder:Prep(4, 8)
+  builder:PrependUint32(a_distance)
+  builder:PrependUint32(a_id)
+  return builder:Offset()
+end
+
+return StructOfStructs