Fix the ownership kind of success bb arg when emitting checked_cast_br` (swiftlang#39347)

Author: meg-gupta

lib/SIL/Utils/DynamicCasts.cpp

@@ -1288,14 +1288,14 @@ void swift::emitIndirectConditionalCastWithScalar(
     return B.emitLoadValueOperation(loc, srcAddr, LoadOwnershipQualifier::Take);
   })();
 
-  B.createCheckedCastBranch(loc, /*exact*/ false, srcValue, targetLoweredType,
-                            targetFormalType, scalarSuccBB, scalarFailBB,
-                            TrueCount, FalseCount);
+  auto *ccb = B.createCheckedCastBranch(
+      loc, /*exact*/ false, srcValue, targetLoweredType, targetFormalType,
+      scalarSuccBB, scalarFailBB, TrueCount, FalseCount);
 
   // Emit the success block.
   B.setInsertionPoint(scalarSuccBB); {
     SILValue succValue = scalarSuccBB->createPhiArgument(
-        targetLoweredType, srcValue.getOwnershipKind());
+        targetLoweredType, ccb->getForwardingOwnershipKind());
 
     switch (consumption) {
     // On success, we take with both take_always and take_on_success.

test/SILOptimizer/mandatory_inlining_ownership.sil

@@ -17,6 +17,8 @@ private class C2 {
 
 class Klass {}
 
+class AnotherKlass {}
+
 sil [transparent] [ossa] @calleeWithGuaranteed : $@convention(thin) (@guaranteed C) -> Builtin.Int64 {
 bb(%0 : @guaranteed $C):
   %1 = ref_element_addr %0 : $C, #C.i
@@ -270,6 +272,23 @@ bb3:
   return %9999 : $()
 }
 
+sil [transparent] [ossa] @term_ossa_checked_cast_addr_br_takealways_callee2 : $@convention(thin) (@in @thick Klass.Type) -> () {
+bb0(%0 : $*@thick Klass.Type):
+  %2 = alloc_stack $AnotherKlass
+  checked_cast_addr_br take_always Klass in %0 : $*@thick Klass.Type to Klass in %2 : $*AnotherKlass, bb1, bb2
+
+bb1:
+  destroy_addr %2 : $*AnotherKlass
+  br bb3
+
+bb2:
+  br bb3
+
+bb3:
+  dealloc_stack %2 : $*AnotherKlass
+  %9999 = tuple()
+  return %9999 : $()
+}
 
 // CHECK-LABEL: sil [ossa] @term_nonossa_checked_cast_addr_br_takealways_caller : $@convention(thin) (@owned Builtin.NativeObject) -> () {
 // CHECK: bb0([[ARG:%.*]] :
@@ -305,6 +324,25 @@ bb0(%0 : @owned $Builtin.NativeObject):
   return %9999 : $()
 }
 
+sil [ossa] @get_klass_type : $@convention(thin) () -> @out @thick Klass.Type
+
+// CHECK-LABEL: sil [ossa] @term_nonossa_checked_cast_addr_br_takealways_caller2 :
+// CHECK: checked_cast_br {{.*}} : $@thick Klass.Type to Klass, [[SUCCESS_BB:bb[0-9]+]], [[FAILURE_BB:bb[0-9]+]], forwarding: @owned
+// CHECK: [[SUCCESS_BB]]({{.*}}@owned $AnotherKlass):
+// CHECK: [[FAILURE_BB]]([[FAILURE_ARG:%.*]] :
+// CHECK: } // end sil function 'term_nonossa_checked_cast_addr_br_takealways_caller2'
+sil [ossa] @term_nonossa_checked_cast_addr_br_takealways_caller2 : $@convention(thin) () -> () {
+bb0:
+  %res = alloc_stack $@thick Klass.Type
+  %2 = function_ref @get_klass_type : $@convention(thin) () -> @out @thick Klass.Type
+  apply %2(%res) : $@convention(thin) () -> @out @thick Klass.Type
+  %3 = function_ref @term_ossa_checked_cast_addr_br_takealways_callee2 : $@convention(thin) (@in @thick Klass.Type) -> ()
+  apply %3(%res) : $@convention(thin) (@in @thick Klass.Type) -> ()
+  dealloc_stack %res : $*@thick Klass.Type
+  %9999 = tuple()
+  return %9999 : $()
+}
+
 sil [transparent] [ossa] @term_ossa_checked_cast_addr_br_takeonsuccess_callee : $@convention(thin) (@owned Builtin.NativeObject) -> () {
 bb0(%0 : @owned $Builtin.NativeObject):
   %1 = alloc_stack $Builtin.NativeObject