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/Vec3.lua

@@ -1,54 +1,70 @@
--- automatically generated by the FlatBuffers compiler, do not modify
+--[[ MyGame.Example.Vec3
 
--- 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 Vec3 = {} -- the module
-local Vec3_mt = {} -- the class metatable
+local Vec3 = {}
+local mt = {}
 
 function Vec3.New()
-    local o = {}
-    setmetatable(o, {__index = Vec3_mt})
-    return o
-end
-function Vec3_mt:Init(buf, pos)
-    self.view = flatbuffers.view.New(buf, pos)
-end
-function Vec3_mt:X()
-    return self.view:Get(flatbuffers.N.Float32, self.view.pos + 0)
-end
-function Vec3_mt:Y()
-    return self.view:Get(flatbuffers.N.Float32, self.view.pos + 4)
-end
-function Vec3_mt:Z()
-    return self.view:Get(flatbuffers.N.Float32, self.view.pos + 8)
-end
-function Vec3_mt:Test1()
-    return self.view:Get(flatbuffers.N.Float64, self.view.pos + 16)
-end
-function Vec3_mt:Test2()
-    return self.view:Get(flatbuffers.N.Uint8, self.view.pos + 24)
-end
-function Vec3_mt:Test3(obj)
-    obj:Init(self.view.bytes, self.view.pos + 26)
-    return obj
-end
-function Vec3.CreateVec3(builder, x, y, z, test1, test2, test3_a, test3_b)
-    builder:Prep(8, 32)
-    builder:Pad(2)
-    builder:Prep(2, 4)
-    builder:Pad(1)
-    builder:PrependInt8(test3_b)
-    builder:PrependInt16(test3_a)
-    builder:Pad(1)
-    builder:PrependUint8(test2)
-    builder:PrependFloat64(test1)
-    builder:Pad(4)
-    builder:PrependFloat32(z)
-    builder:PrependFloat32(y)
-    builder:PrependFloat32(x)
-    return builder:Offset()
+  local o = {}
+  setmetatable(o, {__index = mt})
+  return o
 end
 
-return Vec3 -- return the module
+function mt:Init(buf, pos)
+  self.view = flatbuffers.view.New(buf, pos)
+end
+
+function mt:X()
+  return self.view:Get(flatbuffers.N.Float32, self.view.pos + 0)
+end
+
+function mt:Y()
+  return self.view:Get(flatbuffers.N.Float32, self.view.pos + 4)
+end
+
+function mt:Z()
+  return self.view:Get(flatbuffers.N.Float32, self.view.pos + 8)
+end
+
+function mt:Test1()
+  return self.view:Get(flatbuffers.N.Float64, self.view.pos + 16)
+end
+
+function mt:Test2()
+  return self.view:Get(flatbuffers.N.Uint8, self.view.pos + 24)
+end
+
+function mt:Test3(obj)
+  obj:Init(self.view.bytes, self.view.pos + 26)
+  return obj
+end
+
+function Vec3.CreateVec3(builder, x, y, z, test1, test2, test3_a, test3_b)
+  builder:Prep(8, 32)
+  builder:Pad(2)
+  builder:Prep(2, 4)
+  builder:Pad(1)
+  builder:PrependInt8(test3_b)
+  builder:PrependInt16(test3_a)
+  builder:Pad(1)
+  builder:PrependUint8(test2)
+  builder:PrependFloat64(test1)
+  builder:Pad(4)
+  builder:PrependFloat32(z)
+  builder:PrependFloat32(y)
+  builder:PrependFloat32(x)
+  return builder:Offset()
+end
+
+return Vec3