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]

1 files changed, 1 insertions, 1 deletions

diff --git a/src/test/compile-fail/unreachable-code.rs b/src/test/compile-fail/unreachable-code.rs
index 96adb29cbc8..fb9a6b52018 100644
--- a/src/test/compile-fail/unreachable-code.rs
+++ b/src/test/compile-fail/unreachable-code.rs
@@ -14,5 +14,5 @@
 fn main() {
   loop{}
 
-  let a = 3; //~ ERROR: unreachable statement
+  let a = 3i; //~ ERROR: unreachable statement
 }