[llvm] Don't create the directory hierarchy in the FileCollector...

... if the collected file doesn't exists.

This fixes the situation where LLDB can't create a file when capturing a
reproducer because the parent path doesn't exist, but can during replay
because the file collector created the directory hierarchy even though
the file doesn't exist.

This is covered by the lldb reproducer test suite.

llvm/lib/Support/FileCollector.cpp

@@ -158,14 +158,6 @@ std::error_code FileCollector::copyFiles(bool StopOnError) {
   std::lock_guard<std::mutex> lock(Mutex);
 
   for (auto &entry : VFSWriter.getMappings()) {
-    // Create directory tree.
-    if (std::error_code EC =
-            sys::fs::create_directories(sys::path::parent_path(entry.RPath),
-                                        /*IgnoreExisting=*/true)) {
-      if (StopOnError)
-        return EC;
-    }
-
     // Get the status of the original file/directory.
     sys::fs::file_status Stat;
     if (std::error_code EC = sys::fs::status(entry.VPath, Stat)) {
@@ -174,6 +166,18 @@ std::error_code FileCollector::copyFiles(bool StopOnError) {
       continue;
     }
 
+    // Continue if the file doesn't exist.
+    if (Stat.type() == sys::fs::file_type::file_not_found)
+      continue;
+
+    // Create directory tree.
+    if (std::error_code EC =
+            sys::fs::create_directories(sys::path::parent_path(entry.RPath),
+                                        /*IgnoreExisting=*/true)) {
+      if (StopOnError)
+        return EC;
+    }
+
     if (Stat.type() == sys::fs::file_type::directory_file) {
       // Construct a directory when it's just a directory entry.
       if (std::error_code EC =