[clang] [InstrProf] Add frontend temporal profiling flag (PR #122385)

[Carlo Cabrera via cfe-commits]

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@@ -3035,6 +3035,38 @@ indexed format, regardeless whether it is produced by frontend or the IR pass.
   overhead. ``prefer-atomic`` will be transformed to ``atomic`` when supported
   by the target, or ``single`` otherwise.
 
+.. option:: -fprofile-generate-temporal
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carlocab wrote:

Mild suggestion: `-fgenerate-temporal-profile` or `-ftemporal-profile-generate` seems less awkward to me.

https://github.com/llvm/llvm-project/pull/122385