[llvm] [TLI] Add `noreturn` on `exit`, `_Exit` and `abort` (PR #101623)

[via llvm-commits]

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@@ -66,6 +67,14 @@ static bool setIsCold(Function &F) {
   return true;
 }
 
+static bool setNoReturn(Function &F) {
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goldsteinn wrote:

My understanding of TLI is it should stand alone if say we are linking w.o headers (not that its the most common thing).

I don't have particularly strong preference here, just thought I'd add it when I was doing terminate/__cxa_throw.

https://github.com/llvm/llvm-project/pull/101623