[MoveOnlyAddressChecker] Don't complete phis.

After 874971c, before running address
checking, all lifetimes in the function are completed.  That doesn't
quite work because lifetime completion expects not to encounter
reborrows or their adjacent phis.

Author: nate-chandler

lib/SILOptimizer/Mandatory/MoveOnlyAddressCheckerUtils.cpp

@@ -3997,14 +3997,20 @@ bool MoveOnlyAddressChecker::completeLifetimes() {
   for (auto *block : postOrder->getPostOrder()) {
     for (SILInstruction &inst : reverse(*block)) {
       for (auto result : inst.getResults()) {
+        if (llvm::any_of(result->getUsers(),
+                         [](auto *user) { return isa<BranchInst>(user); })) {
+          continue;
+        }
         if (completion.completeOSSALifetime(result) ==
             LifetimeCompletion::WasCompleted) {
           changed = true;
         }
       }
     }
     for (SILArgument *arg : block->getArguments()) {
-      assert(!arg->isReborrow() && "reborrows not legal at this SIL stage");
+      if (arg->isReborrow()) {
+        continue;
+      }
       if (completion.completeOSSALifetime(arg) ==
           LifetimeCompletion::WasCompleted) {
         changed = true;

test/SILOptimizer/moveonly_addresschecker.sil

@@ -871,3 +871,35 @@ exit:
   %retval = tuple ()
   return %retval : $()
 }
+
+// Test that we don't crash while attempting to complete reborrow lifetimes.
+sil [ossa] @closure_lifetime_fixup_output : $@convention(thin) (@owned NonTrivialStructPair) -> () {
+bb0(%pair : @owned $NonTrivialStructPair):
+  %none = enum $Optional<@callee_guaranteed () -> ()>, #Optional.none!enumelt
+  %none_borrow = begin_borrow %none : $Optional<@callee_guaranteed () -> ()>
+  %stack = alloc_stack $NonTrivialStructPair, let, name "job", argno 1
+  %addr = mark_unresolved_non_copyable_value [consumable_and_assignable] %stack : $*NonTrivialStructPair
+  store %pair to [init] %addr : $*NonTrivialStructPair
+  cond_br undef, bb1, bb3
+
+bb1:
+  end_borrow %none_borrow : $Optional<@callee_guaranteed () -> ()>
+  %closure = partial_apply [callee_guaranteed] undef() : $@convention(thin) () -> ()
+  %some = enum $Optional<@callee_guaranteed () -> ()>, #Optional.some!enumelt, %closure : $@callee_guaranteed () -> ()
+  %some_borrow = begin_borrow %some : $Optional<@callee_guaranteed () -> ()>
+  br bb2
+
+bb2:
+  br bb4(%some_borrow : $Optional<@callee_guaranteed () -> ()>, %some : $Optional<@callee_guaranteed () -> ()>)
+
+bb3:
+  br bb4(%none_borrow : $Optional<@callee_guaranteed () -> ()>, %none : $Optional<@callee_guaranteed () -> ()>)
+
+bb4(%reborrow : @reborrow @guaranteed $Optional<@callee_guaranteed () -> ()>, %maybe : @owned $Optional<@callee_guaranteed () -> ()>):
+  destroy_addr %addr : $*NonTrivialStructPair
+  dealloc_stack %stack : $*NonTrivialStructPair
+  end_borrow %reborrow : $Optional<@callee_guaranteed () -> ()>
+  destroy_value %maybe : $Optional<@callee_guaranteed () -> ()>
+  %retval = tuple ()
+  return %retval : $()
+}