[Parse] Match behaviour of non-delayed parsing when a RB is missing

Author: bnbarham

lib/Parse/ParseDecl.cpp

@@ -5174,7 +5174,9 @@ bool Parser::delayParsingDeclList(SourceLoc LBLoc, SourceLoc &RBLoc,
   if (Tok.is(tok::r_brace)) {
     RBLoc = consumeToken();
   } else {
-    RBLoc = Tok.getLoc();
+    // Non-delayed parsing would set the RB location to the LB if it is missing,
+    // match that behaviour here
+    RBLoc = LBLoc;
     error = true;
   }
   return error;

validation-test/Parse/delayed-members-open-if.swift

@@ -0,0 +1,4 @@
+// RUN: not %target-swift-frontend -typecheck -experimental-skip-all-function-bodies %s
+
+#if os(
+struct Anything {

validation-test/Parse/delayed-members-open-prop-scope.swift

@@ -0,0 +1,6 @@
+// RUN: not %target-swift-frontend -typecheck -experimental-skip-all-function-bodies %s
+
+struct A {
+  let prop: Int = {
+
+struct B {