librustc: Remove the fallback to `int` for integers and `f64` for

floating point numbers for real.

This will break code that looks like:

    let mut x = 0;
    while ... {
        x += 1;
    }
    println!("{}", x);

Change that code to:

    let mut x = 0i;
    while ... {
        x += 1;
    }
    println!("{}", x);

Closes #15201.

[breaking-change]

2 files changed, 2 insertions, 2 deletions

diff --git a/src/libstd/io/fs.rs b/src/libstd/io/fs.rs
index d8e04f18239..bc8447dfa2e 100644
--- a/src/libstd/io/fs.rs
+++ b/src/libstd/io/fs.rs
@@ -1051,7 +1051,7 @@ mod test {
         let initial_msg =   "food-is-yummy";
         let overwrite_msg =    "-the-bar!!";
         let final_msg =     "foo-the-bar!!";
-        let seek_idx = 3;
+        let seek_idx = 3i;
         let mut read_mem = [0, .. 13];
         let tmpdir = tmpdir();
         let filename = &tmpdir.join("file_rt_io_file_test_seek_and_write.txt");
diff --git a/src/libstd/os.rs b/src/libstd/os.rs
index 90f4cbb2577..e0ed8cf667b 100644
--- a/src/libstd/os.rs
+++ b/src/libstd/os.rs
@@ -1816,7 +1816,7 @@ mod tests {
     #[ignore]
     fn test_getenv_big() {
         let mut s = "".to_string();
-        let mut i = 0;
+        let mut i = 0i;
         while i < 100 {
             s.push_str("aaaaaaaaaa");
             i += 1;