Test case for withoutActuallyEscaping of blocks

rdar://38689227

Author: aschwaighofer

test/SILGen/without_actually_escaping_block.swift

@@ -0,0 +1,26 @@
+// RUN: %target-swift-frontend -module-name without_actually_escaping -emit-silgen -enable-sil-ownership %s | %FileCheck %s
+
+// REQUIRES: objc_interop
+
+import Foundation
+
+typealias Callback = @convention(block) () -> Void
+
+// CHECK-LABEL: sil {{.*}} @$S25without_actually_escaping9testBlock5blockyyyXB_tF
+// CHECK: bb0([[ARG:%.*]] : @guaranteed $@convention(block) @noescape () -> ()):
+// CHECK:  [[C1:%.*]] = copy_block [[ARG]]
+// CHECK:  [[B1:%.*]] = begin_borrow [[C1]]
+// CHECK:  [[C2:%.*]] = copy_value [[B1]]
+// CHECK:  [[CVT:%.*]] = convert_function [[C2]] : $@convention(block) @noescape () -> () to $@convention(block) () -> ()
+// CHECK:  [[B2:%.*]] = begin_borrow [[CVT]]
+// CHECK:  [[FN:%.*]] = function_ref @$S25without_actually_escaping9testBlock5blockyyyXB_tFyyyXBXEfU_
+// CHECK:  apply [[FN]]([[B2]])
+// CHECK:  end_borrow [[B2]] from [[CVT]]
+// CHECK:  destroy_value [[CVT]]
+// CHECK:  end_borrow [[B1]] from [[C1]]
+// CHECK:  destroy_value [[C1]]
+// CHECK:  return
+
+func testBlock(block: Callback) {
+  withoutActuallyEscaping(block) { $0() }
+}