Update comments

Author: elsh

test/SILOptimizer/package-cmo-keypath.swift

@@ -14,15 +14,39 @@
 
 //--- Lib.swift
 package protocol PkgProto {
-    var pkgVar: String { get }
+  /// Key path getter for a protocol property has a shared linkage as below, and a function referencing
+  /// this getter (as well as this getter) should not be serialized in Package CMO, even if the `witness_method`
+  /// in this getter has package or public access level.
+  // key path getter for PkgProto.pkgVar : <A>A
+  //  sil shared [thunk] @$s3Lib8PkgProtoP6pkgVarSSvpAaBRzlxTK : $@convention(keypath_accessor_getter) <T where T : PkgProto> (@in_guaranteed T) -> @out String {
+  //  [%0: noescape **, write v**]
+  //  [%1: read v**, write v**, copy v**, destroy v**]
+  //  [global: read,write,copy,destroy,allocate,deinit_barrier]
+  //  // %0                                             // user: %4
+  //  // %1                                             // user: %3
+  //  bb0(%0 : $*String, %1 : $*T):
+  //    %2 = witness_method $T, #PkgProto.pkgVar!getter : <Self where Self : PkgProto> (Self) -> () -> String : $@convention(witness_method: PkgProto) <τ_0_0 where τ_0_0 : PkgProto> (@in_guaranteed τ_0_0) -> @owned String // user: %3
+  //    %3 = apply %2<T>(%1) : $@convention(witness_method: PkgProto) <τ_0_0 where τ_0_0 : PkgProto> (@in_guaranteed τ_0_0) -> @owned String // user: %4
+  //    store %3 to %0 : $*String                       // id: %4
+  //    %5 = tuple ()                                   // user: %6
+  //    return %5 : $()                                 // id: %6
+  //  } // end sil function '$s3Lib8PkgProtoP6pkgVarSSvpAaBRzlxTK'
+  var pkgVar: String { get }
+  
+  // key path getter for PkgProto.pkgVar : <A>A
+  // CHECK-NOT: sil [serialized_for_package] [thunk] [canonical] @$s3Lib8PkgProtoP6pkgVarSSvpAaBRzlxTK : $@convention(keypath_accessor_getter) <T where T : PkgProto> (@in_guaranteed T) -> @out String {
+  // CHECK-NOT: witness_method $T, #PkgProto.pkgVar!getter : <Self where Self : PkgProto> (Self) -> () -> String : $@convention(witness_method: PkgProto) <τ_0_0 where τ_0_0 : PkgProto> (@in_guaranteed τ_0_0) -> @owned String // user: %3
+  // CHECK-NOT: // end sil function '$s3Lib8PkgProtoP6pkgVarSSvpAaBRzlxTK'
 }
 
 package struct Foo: PkgProto {
-    package var pkgVar: String {
-      return "Foo pkgVar"
-    }
+  package var pkgVar: String {
+    return "Foo pkgVar"
+  }
 }
 
+/// testKeyPath references the keypath getter above, s3Lib8PkgProtoP6pkgVarSSvpAaBRzlxTK,
+/// and should not be serialized.
 // testKeyPath<A>(_:)
 // CHECK-NOT: sil package [serialized_for_package] [canonical] @$s3Lib11testKeyPathys0cD0CyxSSGSayxGAA8PkgProtoRzlF : $@convention(thin) <T where T : PkgProto> (@guaranteed Array<T>) -> @owned KeyPath<T, String> {
 // CHECK-NOT: keypath $KeyPath<T, String>, <τ_0_0 where τ_0_0 : PkgProto> (root $τ_0_0; gettable_property $String,  id #PkgProto.pkgVar!getter : <Self where Self : PkgProto> (Self) -> () -> String, getter @$s3Lib8PkgProtoP6pkgVarSSvpAaBRzlxTK : $@convention(keypath_accessor_getter) <τ_0_0 where τ_0_0 : PkgProto> (@in_guaranteed τ_0_0) -> @out String) <T>
@@ -31,11 +55,6 @@ package func testKeyPath<T: PkgProto>(_ array: [T]) -> KeyPath<T, String> {
   return \T.pkgVar
 }
 
-// key path getter for PkgProto.pkgVar : <A>A
-// CHECK-NOT: sil [serialized_for_package] [thunk] [canonical] @$s3Lib8PkgProtoP6pkgVarSSvpAaBRzlxTK : $@convention(keypath_accessor_getter) <T where T : PkgProto> (@in_guaranteed T) -> @out String {
-// CHECK-NOT: witness_method $T, #PkgProto.pkgVar!getter : <Self where Self : PkgProto> (Self) -> () -> String : $@convention(witness_method: PkgProto) <τ_0_0 where τ_0_0 : PkgProto> (@in_guaranteed τ_0_0) -> @owned String // user: %3
-// CHECK-NOT: // end sil function '$s3Lib8PkgProtoP6pkgVarSSvpAaBRzlxTK'
-
 // CHECK: sil_witness_table package [serialized_for_package] Foo: PkgProto module Lib {
 // CHECK:  method #PkgProto.pkgVar!getter: <Self where Self : PkgProto> (Self) -> () -> String : @$s3Lib3FooVAA8PkgProtoA2aDP6pkgVarSSvgTW