EscapeInfo: handle store_borrow

Author: eeckstein

SwiftCompilerSources/Sources/Optimizer/Utilities/EscapeUtils.swift

@@ -509,6 +509,9 @@ fileprivate struct EscapeWalker<V: EscapeVisitor> : ValueDefUseWalker,
       if path.followStores {
         return walkUp(value: store.source, path: path)
       }
+    case let storeBorrow as StoreBorrowInst:
+      assert(operand == storeBorrow.destinationOperand)
+      return walkDownUses(ofAddress: storeBorrow, path: path)
     case let copyAddr as CopyAddrInst:
       if !followLoads(at: path) {
         return .continueWalk
@@ -845,6 +848,8 @@ fileprivate struct EscapeWalker<V: EscapeVisitor> : ValueDefUseWalker,
       return walkUp(value: rea.instance, path: path.push(.classField, index: rea.fieldIndex).with(knownType: nil))
     case let pb as ProjectBoxInst:
       return walkUp(value: pb.box, path: path.push(.classField, index: pb.fieldIndex).with(knownType: nil))
+    case let storeBorrow as StoreBorrowInst:
+      return walkUp(address: storeBorrow.destination, path: path)
     default:
       return isEscaping
     }

test/SILOptimizer/addr_escape_info.sil

@@ -845,3 +845,17 @@ bb0(%0 :  @owned $XandIntClass):
   return %8 : $()
 }
 
+// CHECK-LABEL: Address escape information for test_store_borrow:
+// CHECK:       value:  %2 = store_borrow %0 to %1 : $*X                // users: %4, %3
+// CHECK-NEXT:  End function test_store_borrow
+sil [ossa] @test_store_borrow : $@convention(thin) (@guaranteed X) -> () {
+bb0(%0 :  @guaranteed $X):
+  %1 = alloc_stack $X
+  %2 = store_borrow %0 to %1 : $*X
+  fix_lifetime %2 : $*X
+  end_borrow %2 : $*X
+  dealloc_stack %1 : $*X
+  %3 = tuple ()
+  return %3 : $()
+}
+