fix least significant digits of f128 associated constants

While the numbers are parsed to the correct value, the decimal numbers in the
source were rounded to zero instead of to the nearest, making the literals
different from the values shown in the documentation.

Author: tspiteri

core/src/num/f128.rs

@@ -167,15 +167,15 @@ impl f128 {
     /// [Machine epsilon]: https://en.wikipedia.org/wiki/Machine_epsilon
     /// [`MANTISSA_DIGITS`]: f128::MANTISSA_DIGITS
     #[unstable(feature = "f128", issue = "116909")]
-    pub const EPSILON: f128 = 1.92592994438723585305597794258492731e-34_f128;
+    pub const EPSILON: f128 = 1.92592994438723585305597794258492732e-34_f128;
 
     /// Smallest finite `f128` value.
     ///
     /// Equal to −[`MAX`].
     ///
     /// [`MAX`]: f128::MAX
     #[unstable(feature = "f128", issue = "116909")]
-    pub const MIN: f128 = -1.18973149535723176508575932662800701e+4932_f128;
+    pub const MIN: f128 = -1.18973149535723176508575932662800702e+4932_f128;
     /// Smallest positive normal `f128` value.
     ///
     /// Equal to 2<sup>[`MIN_EXP`]&nbsp;&minus;&nbsp;1</sup>.
@@ -191,7 +191,7 @@ impl f128 {
     /// [`MANTISSA_DIGITS`]: f128::MANTISSA_DIGITS
     /// [`MAX_EXP`]: f128::MAX_EXP
     #[unstable(feature = "f128", issue = "116909")]
-    pub const MAX: f128 = 1.18973149535723176508575932662800701e+4932_f128;
+    pub const MAX: f128 = 1.18973149535723176508575932662800702e+4932_f128;
 
     /// One greater than the minimum possible normal power of 2 exponent.
     ///