[clang] Don't parse MS attributes in `ParseExportDeclaration()`.

[mboehme]

Summary

As @rsmith commented on https://reviews.llvm.org/D111548: "That looks like it's
simply a bug as far as I can tell, and that call can be removed. MS attributes
will be parsed as part of the decl specifier sequence as needed and don't need
to be parsed as declaration attributes."

[aaron.ballman]

LGTM -- I checked as well and these changes are NFC. Thanks!

clang/lib/Parse/ParseDeclCXX.cpp

Decl *Parser::ParseExportDeclaration() {
   Decl *ExportDecl = Actions.ActOnStartExportDecl(
       getCurScope(), ExportLoc,
       Tok.is(tok::l_brace) ? Tok.getLocation() : SourceLocation());
 
   if (Tok.isNot(tok::l_brace)) {
     // FIXME: Factor out a ParseExternalDeclarationWithAttrs.
     ParsedAttributes Attrs(AttrFactory);
     MaybeParseCXX11Attributes(Attrs);
-    MaybeParseMicrosoftAttributes(Attrs);
     ParseExternalDeclaration(Attrs);
     return Actions.ActOnFinishExportDecl(getCurScope(), ExportDecl,
                                          SourceLocation());
   }
 
   BalancedDelimiterTracker T(*this, tok::l_brace);
   T.consumeOpen();
 
   // The Modules TS draft says "An export-declaration shall declare at least one
   // entity", but the intent is that it shall contain at least one declaration.
   if (Tok.is(tok::r_brace) && getLangOpts().ModulesTS) {
     Diag(ExportLoc, diag::err_export_empty)
         << SourceRange(ExportLoc, Tok.getLocation());
   }
 
   while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
          Tok.isNot(tok::eof)) {
     ParsedAttributes Attrs(AttrFactory);
     MaybeParseCXX11Attributes(Attrs);
-    MaybeParseMicrosoftAttributes(Attrs);
     ParseExternalDeclaration(Attrs);
   }
 
   T.consumeClose();
   return Actions.ActOnFinishExportDecl(getCurScope(), ExportDecl,
                                        T.getCloseLocation());
 }