[clang] [llvm] [X86] Support branch hint (PR #97721)

[Shengchen Kan via cfe-commits]

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@@ -0,0 +1,95 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=x86_64-linux -branch-hint -branch-hint-probability-threshold=60 -show-mc-encoding | FileCheck %s
+
+; Design: Insert "ds # encoding: [0x3e]" for condition branches who has high probability to take.
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KanRobert wrote:

`Insert "ds # encoding: [0x3e]"` -> `Add DS segment override prefix` ?

https://github.com/llvm/llvm-project/pull/97721