[clang] [LLVM] Add new attribute `optdebug` to optimize for debugging (PR #66632)

[Mehdi Amini via cfe-commits]

================
@@ -1872,7 +1872,8 @@ example:
     passes make choices that keep the code size of this function as small
     as possible and perform optimizations that may sacrifice runtime
     performance in order to minimize the size of the generated code.
-    This attribute is incompatible with the ``optnone`` attribute.
+    This attribute is incompatible with the ``optdebug`` and ``optnone``
+    attributes.
----------------
joker-eph wrote:

It seems that you're missing the Verifier change to enforce this?

https://github.com/llvm/llvm-project/pull/66632