[clang] [llvm] [clang][docs] Update doc and release note for probe instrumentation (PR #162606)

[Fangrui Song via cfe-commits]

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@@ -2780,6 +2780,25 @@ usual build cycle when using sample profilers for optimization:
        /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^
        code.cc /Fe:code /fuse-ld=lld /link /debug:dwarf
 
+   [OPTIONAL] Pseudo instrumentation can be used as the anchor for accurate
+   profile mapping with the ``-fpseudo-probe-for-profiling`` option.
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MaskRay wrote:

Mention the relation with -fdebug-info-for-profiling

https://github.com/llvm/llvm-project/pull/162606