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/Any.lua

@@ -1,12 +1,20 @@
--- automatically generated by the FlatBuffers compiler, do not modify
+--[[ MyGame.Example.Any
 
--- 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 Any = {
-    NONE = 0,
-    Monster = 1,
-    TestSimpleTableWithEnum = 2,
-    MyGame_Example2_Monster = 3,
+  NONE = 0,
+  Monster = 1,
+  TestSimpleTableWithEnum = 2,
+  MyGame_Example2_Monster = 3,
 }
 
-return Any -- return the module
+return Any