[clang] Make deprecations of some `FileManager` APIs formal (#110014)

Some `FileManager` APIs still return `{File,Directory}Entry` instead of
the preferred `{File,Directory}EntryRef`. These are documented to be
deprecated, but don't have the attribute that warns on their usage. This
PR marks them as such with `LLVM_DEPRECATED()` and replaces their usage
with the recommended counterparts. NFCI.

1 files changed, 3 insertions, 7 deletions

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 5f2a963..240305b 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -427,12 +427,8 @@ static void InitializeFileRemapping(DiagnosticsEngine &Diags,
     }
 
     // Create the file entry for the file that we're mapping from.
-    const FileEntry *FromFile =
-        FileMgr.getVirtualFile(RF.first, ToFile->getSize(), 0);
-    if (!FromFile) {
-      Diags.Report(diag::err_fe_remap_missing_from_file) << RF.first;
-      continue;
-    }
+    FileEntryRef FromFile =
+        FileMgr.getVirtualFileRef(RF.first, ToFile->getSize(), 0);
 
     // Override the contents of the "from" file with the contents of
     // the "to" file.
@@ -1926,7 +1922,7 @@ ModuleLoadResult CompilerInstance::findOrCompileModuleAndReadAST(
 
     // Check whether M refers to the file in the prebuilt module path.
     if (M && M->getASTFile())
-      if (auto ModuleFile = FileMgr->getFile(ModuleFilename))
+      if (auto ModuleFile = FileMgr->getOptionalFileRef(ModuleFilename))
         if (*ModuleFile == M->getASTFile())
           return M;