[flang] Fix to omit #include directives from macro replacement

[pscoro]

Summary

For issue https://github.com/llvm/llvm-project/issues/60317, #include directives should not be run through macro replacement.

[klausler]

Please coordinate with https://reviews.llvm.org/D143469.

[pscoro]

In D143606#4113927, @klausler wrote:

Please coordinate with https://reviews.llvm.org/D143469.

Ah thanks, will close this review

flang/lib/Parser/preprocessor.cpp

 //===-- lib/Parser/preprocessor.cpp ---------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
if (dir.TokenAt(j).ToString() == "<") { // #include <foo>
       while (k < tokens && dir.TokenAt(k) != ">") {
         ++k;
       }
       if (k >= tokens) {
         prescanner.Say(dir.GetIntervalProvenanceRange(j, tokens - j),
             "#include: expected '>' at end of included file"_port_en_US);
       }
       TokenSequence braced{dir, j + 1, k - j - 1};
-      include = ReplaceMacros(braced, prescanner).ToString();
+      include = braced.ToString();
       j = k;
     } else if ((include = dir.TokenAt(j).ToString()).substr(0, 1) == "\"" &&
         include.substr(include.size() - 1, 1) == "\"") { // #include "foo"
       include = include.substr(1, include.size() - 2);
       // #include "foo" starts search in directory of file containing
       // the directive
       auto prov{dir.GetTokenProvenanceRange(dirOffset).start()};
       if (const auto *currentFile{allSources_.GetSourceFile(prov)}) {