auto merge of #6722 : alexcrichton/rust/issue-4219-no-merge-hack, r=brson

Changes the int/uint modules to all use macros instead of using the `merge` attribute. It would be nice to have #4375 resolved as well for this, but that can probably come at a later date.

Closes #4219.

diff --cc src/libsyntax/parse/parser.rs
Simple merge