[llvm] [CodeExtractor] Terminate callsite blocks to new `noreturn` functions with `unreachable` (PR #84682)

[Matt Arsenault via llvm-commits]

================
@@ -1010,6 +1010,18 @@ Function *CodeExtractor::constructFunction(const ValueSet &inputs,
 
     newFunction->addFnAttr(Attr);
   }
+
+  if (NumExitBlocks == 0) {
+    // Mark the new function `noreturn` if applicable. Terminators which resume
+    // exception propagation are treated as returning instructions. This is to
+    // avoid inserting traps after calls to outlined functions which unwind.
+    if (none_of(Blocks, [](const BasicBlock *BB) {
+          const Instruction *Term = BB->getTerminator();
+          return isa<ReturnInst>(Term) || isa<ResumeInst>(Term);
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arsenm wrote:

would be safer to do all_of unreachableinst. This requires maintaining a list of all possible returning terminators (though I guess this was just moved)

https://github.com/llvm/llvm-project/pull/84682