auto merge of #6389 : sonwow/rust/issue-3356, r=bstrie

Fix for #3356

diff --cc src/libcore/io.rs
Simple merge

diff --cc src/libcore/os.rs
Simple merge

diff --cc src/libcore/path.rs
Simple merge

diff --cc src/libcore/rand.rs
Simple merge

diff --cc src/libcore/str.rs
Simple merge

diff --cc src/libcore/vec.rs
Simple merge

diff --cc src/librustc/back/link.rs
Simple merge

diff --cc src/librustc/driver/driver.rs
Simple merge

diff --cc src/librustc/metadata/decoder.rs
Simple merge

diff --cc src/librustc/metadata/encoder.rs
Simple merge

diff --cc src/librustc/metadata/filesearch.rs
Simple merge

diff --cc src/librustc/metadata/loader.rs
Simple merge

diff --cc src/librustc/middle/check_match.rs
Simple merge

diff --cc src/librustc/middle/trans/base.rs
Simple merge

diff --cc src/librustc/middle/ty.rs
Simple merge

diff --cc src/libsyntax/ext/base.rs
Simple merge

diff --cc src/libsyntax/ext/quote.rs
Simple merge

diff --cc src/libsyntax/ext/tt/macro_rules.rs
Simple merge