[NFC] remove unneded header includes

[void]

Summary

This time from clang/Parse.

[aaron.ballman]

LGTM, thank you!

[JDevlieghere]

This breaks the LLDB (modules) build: https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/59738/

clang/include/clang/Parse/LoopHint.h

 //===--- LoopHint.h - Types for LoopHint ------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_PARSE_LOOPHINT_H
 #define LLVM_CLANG_PARSE_LOOPHINT_H
 
-#include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/SourceLocation.h"
-#include "clang/Sema/Ownership.h"
-#include "clang/Sema/ParsedAttr.h"
 
 namespace clang {
 
+class Expr;
+struct IdentifierLoc;
+
 /// Loop optimization hint for loop and unroll pragmas.
 struct LoopHint {
   // Source range of the directive.
   SourceRange Range;
   // Identifier corresponding to the name of the pragma.  "loop" for
   // "#pragma clang loop" directives and "unroll" for "#pragma unroll"
   // hints.
   IdentifierLoc *PragmaNameLoc = nullptr;

clang/include/clang/Parse/Parser.h

 //===--- Parser.h - C Language Parser ---------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 //  This file defines the Parser interface.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_PARSE_PARSER_H
 #define LLVM_CLANG_PARSE_PARSER_H
 
-#include "clang/AST/Availability.h"
-#include "clang/Basic/BitmaskEnum.h"
-#include "clang/Basic/OpenMPKinds.h"
 #include "clang/Basic/OperatorPrecedence.h"
-#include "clang/Basic/Specifiers.h"
-#include "clang/Basic/TokenKinds.h"
 #include "clang/Lex/CodeCompletionHandler.h"
 #include "clang/Lex/Preprocessor.h"
-#include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/Sema.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Frontend/OpenMP/OMPContext.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/SaveAndRestore.h"
-#include <memory>
 #include <optional>
 #include <stack>
 
 namespace clang {
   class PragmaHandler;
   class Scope;
   class BalancedDelimiterTracker;
   class CorrectionCandidateCallback;

clang/include/clang/Parse/RAIIObjectsForParser.h

 // by the parser to manage bits in recursion.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_PARSE_RAIIOBJECTSFORPARSER_H
 #define LLVM_CLANG_PARSE_RAIIOBJECTSFORPARSER_H
 
 #include "clang/Parse/ParseDiagnostic.h"
-#include "clang/Parse/Parser.h"
 #include "clang/Sema/DelayedDiagnostic.h"
-#include "clang/Sema/ParsedTemplate.h"
 #include "clang/Sema/Sema.h"
 
 namespace clang {
+  class ParsedAttributes;
+
   // TODO: move ParsingClassDefinition here.
   // TODO: move TentativeParsingAction here.
 
   /// A RAII object used to temporarily suppress access-like
   /// checking.  Access-like checks are those associated with
   /// controlling the use of a declaration, like C++ access control
   /// errors and deprecation warnings.  They are contextually
   /// dependent, in that they can only be resolved with full