[TextAPI] Introduce TBDv4

[TextAPI] Introduce TBDv4

Summary:
This format introduces new features and platforms
The motivation for this format is to support more than 1 platform since previous versions only supported additional architectures and 1 platform,
for example ios + ios-simulator and macCatalyst.

Reviewers: ributzka, steven_wu

Reviewed By: ributzka

Subscribers: mgorny, hiraditya, mgrang, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67529

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@374058 91177308-0d34-0410-b5e6-96231b3b80d8