Fix store_borrow's end_borrows in GenericCloner when lifetime boundary cannot be found

Make sure end_borrows are inserted before dealloc_stack. Instead of inserting them at
function exits. Insert before dealloc_stack of destination.

Author: meg-gupta

lib/SILOptimizer/Utils/GenericCloner.cpp

@@ -260,8 +260,9 @@ void GenericCloner::postFixUp(SILFunction *f) {
       scopedAddress.endScopeAtLivenessBoundary(&storeBorrowLiveness);
       continue;
     }
-    for (auto *exit : FunctionExits) {
-      scopedAddress.createScopeEnd(exit->getIterator(),
+    auto *alloc = cast<AllocStackInst>(sbi->getDest());
+    for (auto *dealloc : alloc->getUsersOfType<DeallocStackInst>()) {
+      scopedAddress.createScopeEnd(dealloc->getIterator(),
                                    RegularLocation::getAutoGeneratedLocation());
     }
   }

test/SIL/store_borrow_verify_errors.sil

@@ -1,4 +1,7 @@
-// RUN: %target-sil-opt -verify-continue-on-failure -enable-sil-verify-all=0 %s -o /dev/null 2>&1 | %FileCheck %s 
+// RUN: %target-sil-opt -dont-abort-on-memory-lifetime-errors -verify-continue-on-failure -enable-sil-verify-all=0 %s -o /dev/null 2>&1 | %FileCheck %s 
+
+// Memory lifetime verifier also raises errors in some of these cases, add dont-abort-on-memory-lifetime-errors so that we don't check it's output.
+// Memory lifetime verifier cannot subsume this because the verification is disabled on unreachable paths.
 
 import Builtin
 

test/SILOptimizer/specialize_ossa.sil

@@ -32,6 +32,14 @@ bb0(%0 : $Builtin.NativeObject):
   return %9999 : $()
 }
 
+// CHECK-LABEL: sil shared [noinline] [ossa] @$s33XXX_foo_guaranteed_generic_returnBo_Tg5 :
+// CHECK:  [[S1:%.*]] = alloc_stack $Builtin.NativeObject
+// CHECK:  [[S2:%.*]] = alloc_stack $Builtin.NativeObject
+// CHECK:  [[SBI:%.*]] = store_borrow %0 to [[S2]] : $*Builtin.NativeObject
+// CHECK:  end_borrow [[SBI]] : $*Builtin.NativeObject
+// CHECK:  dealloc_stack [[S2]] : $*Builtin.NativeObject
+// CHECK-LABEL: } // end sil function '$s33XXX_foo_guaranteed_generic_returnBo_Tg5'
+
 // CHECK-LABEL: sil [ossa] @exp1 : $@convention(thin) () -> () {
 // CHECK-NOT: apply
 // Call of specialized initializer: <Int32>
@@ -115,7 +123,6 @@ bb0(%0 : $*T, %1 : $*XXX<T>):
   return %9 : $Int32                              // id: %11
 }
 
-
 sil [ossa] [noinline] @XXX_foo_guaranteed_generic_return : $@convention(method) <T> (@in_guaranteed T, @in XXX<T>) -> @out T {
 bb0(%0 : $*T, %1 : $*T, %2 : $*XXX<T>):
   %3 = address_to_pointer %1 : $*T to $Builtin.RawPointer