[clang] [SemaCXX] Recognise initializer_list injected-class-name types as initializer_lists (PR #90210)

[Mital Ashok via cfe-commits]

MitalAshok wrote:

Original Differential revision: https://reviews.llvm.org/D156064

Doesn't appear that anything has changed since, just rebased the changes.

https://github.com/llvm/llvm-project/pull/90210