Skip fast path for dec2flt when optimize_for_size

library/core/src/num/dec2flt/mod.rs

@@ -250,9 +250,11 @@ pub fn dec2flt<F: RawFloat>(s: &str) -> Result<F, ParseFloatError> {
         None => return Err(pfe_invalid()),
     };
     num.negative = negative;
+    if cfg!(not(feature = "optimize_for_size")) {
         if let Some(value) = num.try_fast_path::<F>() {
             return Ok(value);
         }
+    }
 
     // If significant digits were truncated, then we can have rounding error
     // only if `mantissa + 1` produces a different result. We also avoid