[clang] [Parse] Avoid mixing enum and non-enum types in ternary expressions. NFC.

This fixes the following kind of warning when compiled with GCC:

    ../../clang/lib/Parse/ParseStmt.cpp: In member function ‘clang::StmtResult clang::Parser::ParseCXXTryBlockCommon(clang::SourceLocation, bool)’:
    ../../clang/lib/Parse/ParseStmt.cpp:2534:40: warning: enumerated and non-enumerated type in conditional expression [-Wextra]
     2534 |                                 (FnTry ? Scope::FnTryCatchScope : 0)));
          |                                  ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Use `Scope::NoScope` instead of literal 0 as fallback in the
ternary expressions.

Author: mstorsjo

clang/lib/Parse/ParseDecl.cpp

@@ -6813,10 +6813,10 @@ void Parser::ParseDirectDeclarator(Declarator &D) {
       bool IsFunctionDeclaration = D.isFunctionDeclaratorAFunctionDeclaration();
       // Enter function-declaration scope, limiting any declarators to the
       // function prototype scope, including parameter declarators.
-      ParseScope PrototypeScope(this,
-                                Scope::FunctionPrototypeScope|Scope::DeclScope|
-                                (IsFunctionDeclaration
-                                   ? Scope::FunctionDeclarationScope : 0));
+      ParseScope PrototypeScope(
+          this, Scope::FunctionPrototypeScope | Scope::DeclScope |
+                    (IsFunctionDeclaration ? Scope::FunctionDeclarationScope
+                                           : Scope::NoScope));
 
       // The paren may be part of a C++ direct initializer, eg. "int x(1);".
       // In such a case, check if we actually have a function declarator; if it
@@ -7097,8 +7097,9 @@ void Parser::ParseParenDeclarator(Declarator &D) {
   // function prototype scope, including parameter declarators.
   ParseScope PrototypeScope(this,
                             Scope::FunctionPrototypeScope | Scope::DeclScope |
-                            (D.isFunctionDeclaratorAFunctionDeclaration()
-                               ? Scope::FunctionDeclarationScope : 0));
+                                (D.isFunctionDeclaratorAFunctionDeclaration()
+                                     ? Scope::FunctionDeclarationScope
+                                     : Scope::NoScope));
   ParseFunctionDeclarator(D, attrs, T, false, RequiresArg);
   PrototypeScope.Exit();
 }

clang/lib/Parse/ParseObjc.cpp

@@ -3295,9 +3295,9 @@ void Parser::ParseLexedObjCMethodDefs(LexedMethod &LM, bool parseMethod) {
   assert(Tok.isOneOf(tok::l_brace, tok::kw_try, tok::colon) &&
          "Inline objective-c method not starting with '{' or 'try' or ':'");
   // Enter a scope for the method or c-function body.
-  ParseScope BodyScope(this, (parseMethod ? Scope::ObjCMethodScope : 0) |
-                                 Scope::FnScope | Scope::DeclScope |
-                                 Scope::CompoundStmtScope);
+  ParseScope BodyScope(
+      this, (parseMethod ? Scope::ObjCMethodScope : Scope::NoScope) |
+                Scope::FnScope | Scope::DeclScope | Scope::CompoundStmtScope);
   Sema::FPFeaturesStateRAII SaveFPFeatures(Actions);
 
   // Tell the actions module that we have entered a method or c-function definition

clang/lib/Parse/ParseStmt.cpp

@@ -2529,9 +2529,9 @@ StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc, bool FnTry) {
     return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
 
   StmtResult TryBlock(ParseCompoundStatement(
-      /*isStmtExpr=*/false, Scope::DeclScope | Scope::TryScope |
-                                Scope::CompoundStmtScope |
-                                (FnTry ? Scope::FnTryCatchScope : 0)));
+      /*isStmtExpr=*/false,
+      Scope::DeclScope | Scope::TryScope | Scope::CompoundStmtScope |
+          (FnTry ? Scope::FnTryCatchScope : Scope::NoScope)));
   if (TryBlock.isInvalid())
     return TryBlock;
 
@@ -2593,9 +2593,9 @@ StmtResult Parser::ParseCXXCatchBlock(bool FnCatch) {
   // C++ 3.3.2p3:
   // The name in a catch exception-declaration is local to the handler and
   // shall not be redeclared in the outermost block of the handler.
-  ParseScope CatchScope(this, Scope::DeclScope | Scope::ControlScope |
-                                  Scope::CatchScope |
-                                  (FnCatch ? Scope::FnTryCatchScope : 0));
+  ParseScope CatchScope(
+      this, Scope::DeclScope | Scope::ControlScope | Scope::CatchScope |
+                (FnCatch ? Scope::FnTryCatchScope : Scope::NoScope));
 
   // exception-declaration is equivalent to '...' or a parameter-declaration
   // without default arguments.