[clang] [llvm] [AArch64][docs] Add release notes for FUJITSU-MONAKA support (PR #120684)

[Yuta Mukai via llvm-commits]

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@@ -977,6 +977,10 @@ Arm and AArch64 Support
   in leaf functions after enabling ``-fno-omit-frame-pointer``, you can do so by adding
   the ``-momit-leaf-frame-pointer`` option.
 
+- Support has been added for the following processors (-mcpu identifiers in parenthesis):
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ytmukai wrote:

It should be added that this is for AArch64 target.

https://github.com/llvm/llvm-project/pull/120684