Avoid rare deadlock inside SHCreateDirectoyExW.

Replace call to SHCreateDirectoyExW on the win32 platform with multiple
calls to CreateDirectoryW to avoid deadlock within CoUninitialize which
is called from SHCreateDirectoyExW. MSDN states that calling
CoInitialize during DllMain is prohibited. SHCreateDirectoyExW
internally calls CoInitialize, thus calling SHCreateDirectoyExW inside
the DllMain is prohibited as well.

renderdoc/os/win32/win32_stringio.cpp

@@ -240,7 +240,36 @@ void CreateParentDirectory(const string &filename)
     if(wfn[i] == L'/')
       wfn[i] = L'\\';
 
-  SHCreateDirectoryExW(NULL, wfn.c_str(), NULL);
+  // Remove trailing \\s
+  size_t trailingSeperatorPos = wfn.find_last_of(L'\\');
+  while(trailingSeperatorPos == wfn.length() - 1)
+  {
+    wfn.erase(trailingSeperatorPos);
+    trailingSeperatorPos = wfn.find_last_of(L'\\');
+  }
+
+  // Find all directories we need to create
+  std::vector<wstring> directoriesToCreate;
+  while(!wfn.empty())
+  {
+    DWORD fileAttributes = GetFileAttributesW(wfn.c_str());
+    if(fileAttributes != INVALID_FILE_ATTRIBUTES)
+      break;
+
+    directoriesToCreate.push_back(wfn);
+
+    size_t seperatorPos = wfn.find_last_of(L'\\');
+    if(seperatorPos == string::npos)
+      break;
+    else
+      wfn = wfn.substr(0, seperatorPos);
+  }
+
+  // Create the directories in reverse order
+  for(ptrdiff_t i = directoriesToCreate.size() - 1; i >= 0; i--)
+  {
+    CreateDirectoryW(directoriesToCreate[i].c_str(), NULL);
+  }
 }
 
 string GetReplayAppFilename()