[clang] Fix CXXNewExpr end source location for 'new struct S' (#92266)

Currently, `new struct S` fails to set any valid end source location
because the token corresponding to `S` is consumed in
`ParseClassSpecifier` and is not accessible in the
`ParseDeclarationSpecifiers` that normally sets the end source location.

Fixes #35300

Author: necto

clang-tools-extra/test/clang-tidy/checkers/modernize/make-unique.cpp

@@ -606,11 +606,8 @@ void invoke_template() {
   template_fun(foo);
 }
 
-void no_fix_for_invalid_new_loc() {
-  // FIXME: Although the code is valid, the end location of `new struct Base` is
-  // invalid. Correct it once https://bugs.llvm.org/show_bug.cgi?id=35952 is
-  // fixed.
+void fix_for_c_style_struct() {
   auto T = std::unique_ptr<Base>(new struct Base);
   // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use std::make_unique instead
-  // CHECK-FIXES: auto T = std::unique_ptr<Base>(new struct Base);
+  // CHECK-FIXES: auto T = std::make_unique<Base>();
 }

clang/lib/Parse/ParseDeclCXX.cpp

@@ -1883,6 +1883,7 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
   if (Tok.is(tok::identifier)) {
     Name = Tok.getIdentifierInfo();
     NameLoc = ConsumeToken();
+    DS.SetRangeEnd(NameLoc);
 
     if (Tok.is(tok::less) && getLangOpts().CPlusPlus) {
       // The name was supposed to refer to a template, but didn't.

clang/test/AST/ast-dump-expr.cpp

@@ -583,3 +583,10 @@ void NonADLCall3() {
   f(x);
 }
 } // namespace test_adl_call_three
+
+namespace GH35300 {
+struct Sock {};
+void leakNewFn() { new struct Sock; }
+// CHECK: CXXNewExpr {{.*}} <col:20, col:31> 'struct Sock *'
+}
+