[NameLookup] Retain invalid decls when filtering via access path

Fixes missing declarations in the completions list due to their type
being invalid.

Resolves rdar://70704835

Author: bnbarham

lib/AST/NameLookup.cpp

@@ -138,8 +138,6 @@ void DebuggerClient::anchor() {}
 void AccessFilteringDeclConsumer::foundDecl(
     ValueDecl *D, DeclVisibilityKind reason,
     DynamicLookupInfo dynamicLookupInfo) {
-  if (D->hasInterfaceType() && D->isInvalid())
-    return;
   if (!D->isAccessibleFrom(DC))
     return;
 

test/IDE/complete_sequence_invalid.swift

@@ -0,0 +1,19 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-ide-test -batch-code-completion -source-filename %s -filecheck %raw-FileCheck -completion-output-dir %t
+
+// GLOBAL: Decl[GlobalVar]/CurrModule:         invalidDecl[#<<error type>>#];
+let invalidDecl = INVALID
+
+struct S {
+  // MEMBER: Decl[InstanceMethod]/CurrNominal:   invalidMethod()[#<<error type>>#];
+  func invalidMethod() -> INVALID
+}
+
+func test() {
+  #^GLOBAL_1?check=GLOBAL^#
+  #^GLOBAL_2?check=GLOBAL^#
+}
+
+func testMember(val: S) {
+  val.#^MEMBER_1?check=MEMBER^##^MEMBER_2?check=MEMBER^#
+}