clang-include-fixer was recently updated to be python3-compatible.
However, an exception handling clause was improperly using the deprecated `message` property of Exception classes, so the code was not yet entirely python3-compatible.
Differential Revision: https://reviews.llvm.org/D70902
Makes the name of this directory consistent with the names of the other
directories in clang-tools-extra.
Similar to r356254. No intended behavior change.
Differential Revision: https://reviews.llvm.org/D59750
llvm-svn: 356897