Make float parsing "." return Err

This makes both of the following return Err:

    ".".parse::<f32>()
    ".".parse::<f64>()

This is a [breaking-change], which the libs team have classified as a
bug fix.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/libcoretest/num/dec2flt/mod.rs b/src/libcoretest/num/dec2flt/mod.rs
index 0c92b2fe2a7..7b25333e21e 100644
--- a/src/libcoretest/num/dec2flt/mod.rs
+++ b/src/libcoretest/num/dec2flt/mod.rs
@@ -98,7 +98,8 @@ fn fast_path_correct() {
 
 #[test]
 fn lonely_dot() {
-    assert_eq!(".".parse(), Ok(0.0));
+    assert!(".".parse::<f32>().is_err());
+    assert!(".".parse::<f64>().is_err());
 }
 
 #[test]