Revert "[Sema] Record type of identity key paths in the constraint system"

This reverts commit 7577496.

Author: ahoppen

lib/Sema/CSGen.cpp

@@ -3232,7 +3232,7 @@ namespace {
           break;
         }
         case KeyPathExpr::Component::Kind::Identity:
-          break;
+          continue;
         case KeyPathExpr::Component::Kind::DictionaryKey:
           llvm_unreachable("DictionaryKey only valid in #keyPath");
           break;

test/IDE/complete_swift_key_path.swift

@@ -35,7 +35,6 @@
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=GENERIC_KEY_PATH_BASE | %FileCheck %s -check-prefix=PERSONTYPE-DOT
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=GENERIC_KEY_PATH_RESULT | %FileCheck %s -check-prefix=PERSONTYPE-DOT
 
-// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=COMPLETE_AFTER_SELF | %FileCheck %s -check-prefix=OBJ-NODOT
 class Person {
     var name: String
     var friends: [Person] = []
@@ -192,7 +191,3 @@ func genericKeyPathResult<KeyPathResult>(id: KeyPath<Person, KeyPathResult>) {
   genericKeyPathResult(\.#^GENERIC_KEY_PATH_RESULT^#)
   // Same as TYPE_DOT.
 }
-
-func completeAfterSelf(people: [Person]) {
-  people.map(\.self#^COMPLETE_AFTER_SELF^#)
-}