[clang] [Clang] Enable -fextend-lifetimes at -Og (PR #118026)

[Jeremy Morse via cfe-commits]

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@@ -441,6 +441,10 @@ Modified Compiler Flags
   ``memset`` and similar functions for which it is a documented undefined
   behavior. It is implied by ``-Wnontrivial-memaccess``
 
+- The ``-Og`` optimization flag now sets ``-fextend-lifetimes``, a new compiler
+  flag, resulting in slightly reduced optimization compared to ``-O1`` in
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jmorse wrote:

Can we just say "trading optimization for improved..." to indicate that this is a conscious decision the developer might make?

https://github.com/llvm/llvm-project/pull/118026