Stack from ghstack:

• [jit] add for in dict support #22006 [jit] add for in dict support
• [jit] add for in string support #21990 [jit] add for in string support
• [jit] support iteration tuple unpacking #21985 [jit] support iteration tuple unpacking
• [jit] refactor all for in range/tensor tests to be together with other for loop tests #21950 [jit] refactor all for in range/tensor tests to be together with other for loop tests
• [jit] Tree based Iterator infrastructure: for in range/list/tensor/zip/enumerate #21801 [jit] Tree based Iterator infrastructure: for in range/list/tensor/zip/enumerate
• [jit] more complete tuple assignments #21949 [jit] more complete tuple assignments

Summary:

This support more complete tuple assignments like nested tuple assignments, also serve as a pre-requisite for iterables

Differential Revision: D15948550