Add unsafeAddress dependency SILGen test case

Author: atrick

test/SILGen/addressor_dependence.swift

@@ -0,0 +1,29 @@
+// RUN: %target-swift-emit-silgen %s | %FileCheck %s
+
+public class C {}
+
+public struct BoxC {
+  let storage: AnyObject?
+  let pointer: UnsafePointer<C>
+
+  subscript() -> C {
+    unsafeAddress {
+      pointer
+    }
+  }
+}
+
+// The addressor result must explicitly dependend on the apply's 'self' arg.
+//
+// CHECK-LABEL: sil [ossa] @$s20addressor_dependence21testAddressorLifetime3boxAA1CCAA4BoxCVn_tF : $@convention(thin) (@owned BoxC) -> @owned C {
+// CHECK: bb0(%0 : @noImplicitCopy @_eagerMove @owned $BoxC):
+// CHECK: [[MV:%.*]] = moveonlywrapper_to_copyable [guaranteed]
+// CHECK: [[APPLY:%.*]] = apply %{{.*}}([[MV]]) : $@convention(method) (@guaranteed BoxC) -> UnsafePointer<C>
+// CHECK: [[P:%.*]] = struct_extract [[APPLY]], #UnsafePointer._rawValue
+// CHECK: [[A:%.*]] = pointer_to_address [[P]] to [strict] $*C
+// CHECK: [[MD:%.*]] = mark_dependence [unresolved] [[A]] on [[MV]]
+// CHECK: begin_access [read] [unsafe] [[MD]]
+// CHECK-LABEL: } // end sil function '$s20addressor_dependence21testAddressorLifetime3boxAA1CCAA4BoxCVn_tF'
+public func testAddressorLifetime(box: consuming BoxC) -> C {
+  box[]
+}