[clang] [llvm] [LLVM] Rename `Type::getTruncated()` and `Type::getExtended()` (PR #196528)

[Rahul Joshi via cfe-commits]

jurahul wrote:

These are the new names @s-barannikov suggested in the other PR. PTAL and see if these are better names.

https://github.com/llvm/llvm-project/pull/196528