Add lifetime dependence unit tests for syntesized accessors.

Author: atrick

test/SILOptimizer/lifetime_dependence/accessors.swift

@@ -0,0 +1,55 @@
+// RUN: %target-swift-emit-sil -enable-experimental-feature Lifetimes -primary-file %s | %FileCheck %s
+
+// REQUIRES: swift_feature_Lifetimes
+
+struct NE : ~Escapable {
+  let _p: UnsafeRawPointer
+
+  @_lifetime(borrow p)
+  init(_ p: UnsafeRawPointer) { self._p = p }
+}
+
+struct NEStoredProp : ~Copyable, ~Escapable {
+  var ne: NE
+}
+
+struct NCNE : ~Copyable, ~Escapable {
+  let _p: UnsafeRawPointer
+
+  @_lifetime(borrow p)
+  init(_ p: UnsafeRawPointer) {
+    self._p = p
+  }
+}
+
+struct NCNEHolder : ~Copyable, ~Escapable {
+  var p: UnsafeRawPointer
+
+  // this cannot be public in order to synthesize the _read accessor.
+  var ncneBorrow: NCNE {
+    // CHECK-LABEL: sil{{.*}} @$s9accessors10NCNEHolderV10ncneBorrowAA4NCNEVvr : $@yield_once @convention(method) (@guaranteed NCNEHolder) -> @lifetime(borrow 0) @yields @guaranteed NCNE {
+    @_lifetime(borrow self)
+    borrowing get {
+      _overrideLifetime(NCNE(p), borrowing: self)
+    }
+    // CHECK-LABEL: sil{{.*}} @$s9accessors10NCNEHolderV10ncneBorrowAA4NCNEVvM : $@yield_once @convention(method) (@lifetime(copy 0) @inout NCNEHolder) -> @lifetime(borrow 0) @yields @inout NCNE {
+    @_lifetime(self: copy self)
+    set {
+      p = newValue._p
+    }
+  }
+
+  // this cannot be public in order to synthesize the _read accessor.
+  var ncneCopy: NCNE {
+    // CHECK-LABEL: sil{{.*}} @$s9accessors10NCNEHolderV8ncneCopyAA4NCNEVvr : $@yield_once @convention(method) (@guaranteed NCNEHolder) -> @lifetime(copy 0) @yields @guaranteed NCNE {
+    @_lifetime(copy self)
+    borrowing get {
+      _overrideLifetime(NCNE(p), copying: self)
+    }
+    // CHECK-LABEL: sil{{.*}} @$s9accessors10NCNEHolderV8ncneCopyAA4NCNEVvM : $@yield_once @convention(method) (@lifetime(copy 0) @inout NCNEHolder) -> @lifetime(copy 0) @yields @inout NCNE {
+    @_lifetime(self: copy self)
+    set {
+      p = newValue._p
+    }
+  }
+}