[CSDiagnostics] Verify that member is in collection context

`MissingMemberFailure::diagnoseInLiteralCollectionContext`
should verify that a parent (or parent of a parent) expression
is indeed a collection expression instead of checking types.

Resolves: rdar://91452726

Author: xedin

lib/Sema/CSDiagnostics.cpp

@@ -3976,17 +3976,14 @@ bool MissingMemberFailure::diagnoseInLiteralCollectionContext() const {
   if (!parentExpr)
     return false;
 
-  auto parentType = getType(parentExpr);
+  // This could happen if collection is a dictionary literal i.e.
+  // ["a": .test] - the element is a tuple - ("a", .test).
+  if (isExpr<TupleExpr>(parentExpr))
+    parentExpr = findParentExpr(parentExpr);
 
-  if (!parentType->isKnownStdlibCollectionType() && !parentType->is<TupleType>())
+  if (!isExpr<CollectionExpr>(parentExpr))
     return false;
 
-  if (isa<TupleExpr>(parentExpr)) {
-    parentExpr = findParentExpr(parentExpr);
-    if (!parentExpr)
-      return false;
-  }
-
   if (auto *defaultableVar =
           getRawType(parentExpr)->getAs<TypeVariableType>()) {
     if (solution.DefaultedConstraints.count(

test/expr/closure/multi_statement.swift

@@ -546,3 +546,23 @@ func test_conflicting_pattern_vars() {
     }
   }
 }
+
+// rdar://91452726 - crash in MissingMemberFailure::diagnoseInLiteralCollectionContext
+struct Test {
+  struct ID {
+  }
+
+  enum E : Hashable, Equatable {
+  case id
+  }
+
+  var arr: [(ID, E)]
+
+  func test() {
+    _ = arr.map { v in
+      switch v {
+      case .id: return true // expected-error {{value of tuple type '(Test.ID, Test.E)' has no member 'id'}}
+      }
+    }
+  }
+}