message: Add missing undefined check for toolchains
diff: @@ -393,9 +393,9 @@ export class CppConfigurationProvider implements cpt.CustomConfigurationProvider
  const lang = fileGroup.language === "RC" ? undefined : fileGroup.language;
  // First try to get toolchain values directly reported by CMake. Check the
  // group's language compiler, then the C++ compiler, then the C compiler.
  - const comp_toolchains = opts.codeModel.toolchains.get(lang ?? "")
  - || opts.codeModel.toolchains.get('CXX')
  - || opts.codeModel.toolchains.get('C');
  + const comp_toolchains = opts.codeModel.toolchains?.get(lang ?? "")
  + || opts.codeModel.toolchains?.get('CXX')
  + || opts.codeModel.toolchains?.get('C');
  // If none of those work, fall back to the same order, but in the cache.
  const comp_cache = opts.cache.get(`CMAKE_${lang}_COMPILER`)
  || opts.cache.get('CMAKE_CXX_COMPILER')
  