Ensure that we run late-lowering over ccallable funcs (#47226)

Author: vchuravy

src/llvm-final-gc-lowering.cpp

@@ -304,7 +304,7 @@ bool FinalLowerGC::runOnFunction(Function &F)
     LLVM_DEBUG(dbgs() << "FINAL GC LOWERING: Processing function " << F.getName() << "\n");
     // Check availability of functions again since they might have been deleted.
     initFunctions(*F.getParent());
-    if (!pgcstack_getter)
+    if (!pgcstack_getter && !adoptthread_func)
         return false;
 
     // Look for a call to 'julia.get_pgcstack'.

src/llvm-late-gc-lowering.cpp

@@ -2720,7 +2720,7 @@ void LateLowerGCFrame::PlaceRootsAndUpdateCalls(std::vector<int> &Colors, State
 bool LateLowerGCFrame::runOnFunction(Function &F, bool *CFGModified) {
     initAll(*F.getParent());
     LLVM_DEBUG(dbgs() << "GC ROOT PLACEMENT: Processing function " << F.getName() << "\n");
-    if (!pgcstack_getter)
+    if (!pgcstack_getter && !adoptthread_func)
         return CleanupIR(F, nullptr, CFGModified);
 
     pgcstack = getPGCstack(F);