Reduce patching of libcore a bit

These parts are no longer necessary as of #627

patches/0002-Disable-u128-and-i128-in-libcore.patch

@@ -68,209 +68,6 @@ index d0ee5fa..d02c454 100644
  #[cfg(target_pointer_width = "16")]
  macro_rules! ptr_width {
      () => { 2 }
-diff --git a/src/libcore/time.rs b/src/libcore/time.rs
-index ae6d807..4414e07 100644
---- a/src/libcore/time.rs
-+++ b/src/libcore/time.rs
-@@ -534,198 +534,6 @@ impl Duration {
-     pub const fn as_secs_f32(&self) -> f32 {
-         (self.secs as f32) + (self.nanos as f32) / (NANOS_PER_SEC as f32)
-     }
--
--    /// Creates a new `Duration` from the specified number of seconds represented
--    /// as `f64`.
--    ///
--    /// # Panics
--    /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
--    ///
--    /// # Examples
--    /// ```
--    /// #![feature(duration_float)]
--    /// use std::time::Duration;
--    ///
--    /// let dur = Duration::from_secs_f64(2.7);
--    /// assert_eq!(dur, Duration::new(2, 700_000_000));
--    /// ```
--    #[unstable(feature = "duration_float", issue = "54361")]
--    #[inline]
--    pub fn from_secs_f64(secs: f64) -> Duration {
--        const MAX_NANOS_F64: f64 =
--            ((u64::MAX as u128 + 1)*(NANOS_PER_SEC as u128)) as f64;
--        let nanos =  secs * (NANOS_PER_SEC as f64);
--        if !nanos.is_finite() {
--            panic!("got non-finite value when converting float to duration");
--        }
--        if nanos >= MAX_NANOS_F64 {
--            panic!("overflow when converting float to duration");
--        }
--        if nanos < 0.0 {
--            panic!("underflow when converting float to duration");
--        }
--        let nanos =  nanos as u128;
--        Duration {
--            secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
--            nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
--        }
--    }
--
--    /// Creates a new `Duration` from the specified number of seconds represented
--    /// as `f32`.
--    ///
--    /// # Panics
--    /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
--    ///
--    /// # Examples
--    /// ```
--    /// #![feature(duration_float)]
--    /// use std::time::Duration;
--    ///
--    /// let dur = Duration::from_secs_f32(2.7);
--    /// assert_eq!(dur, Duration::new(2, 700_000_000));
--    /// ```
--    #[unstable(feature = "duration_float", issue = "54361")]
--    #[inline]
--    pub fn from_secs_f32(secs: f32) -> Duration {
--        const MAX_NANOS_F32: f32 =
--            ((u64::MAX as u128 + 1)*(NANOS_PER_SEC as u128)) as f32;
--        let nanos =  secs * (NANOS_PER_SEC as f32);
--        if !nanos.is_finite() {
--            panic!("got non-finite value when converting float to duration");
--        }
--        if nanos >= MAX_NANOS_F32 {
--            panic!("overflow when converting float to duration");
--        }
--        if nanos < 0.0 {
--            panic!("underflow when converting float to duration");
--        }
--        let nanos =  nanos as u128;
--        Duration {
--            secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
--            nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
--        }
--    }
--
--    /// Multiplies `Duration` by `f64`.
--    ///
--    /// # Panics
--    /// This method will panic if result is not finite, negative or overflows `Duration`.
--    ///
--    /// # Examples
--    /// ```
--    /// #![feature(duration_float)]
--    /// use std::time::Duration;
--    ///
--    /// let dur = Duration::new(2, 700_000_000);
--    /// assert_eq!(dur.mul_f64(3.14), Duration::new(8, 478_000_000));
--    /// assert_eq!(dur.mul_f64(3.14e5), Duration::new(847_800, 0));
--    /// ```
--    #[unstable(feature = "duration_float", issue = "54361")]
--    #[inline]
--    pub fn mul_f64(self, rhs: f64) -> Duration {
--        Duration::from_secs_f64(rhs * self.as_secs_f64())
--    }
--
--    /// Multiplies `Duration` by `f32`.
--    ///
--    /// # Panics
--    /// This method will panic if result is not finite, negative or overflows `Duration`.
--    ///
--    /// # Examples
--    /// ```
--    /// #![feature(duration_float)]
--    /// use std::time::Duration;
--    ///
--    /// let dur = Duration::new(2, 700_000_000);
--    /// // note that due to rounding errors result is slightly different
--    /// // from 8.478 and 847800.0
--    /// assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_640));
--    /// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847799, 969_120_256));
--    /// ```
--    #[unstable(feature = "duration_float", issue = "54361")]
--    #[inline]
--    pub fn mul_f32(self, rhs: f32) -> Duration {
--        Duration::from_secs_f32(rhs * self.as_secs_f32())
--    }
--
--    /// Divide `Duration` by `f64`.
--    ///
--    /// # Panics
--    /// This method will panic if result is not finite, negative or overflows `Duration`.
--    ///
--    /// # Examples
--    /// ```
--    /// #![feature(duration_float)]
--    /// use std::time::Duration;
--    ///
--    /// let dur = Duration::new(2, 700_000_000);
--    /// assert_eq!(dur.div_f64(3.14), Duration::new(0, 859_872_611));
--    /// // note that truncation is used, not rounding
--    /// assert_eq!(dur.div_f64(3.14e5), Duration::new(0, 8_598));
--    /// ```
--    #[unstable(feature = "duration_float", issue = "54361")]
--    #[inline]
--    pub fn div_f64(self, rhs: f64) -> Duration {
--        Duration::from_secs_f64(self.as_secs_f64() / rhs)
--    }
--
--    /// Divide `Duration` by `f32`.
--    ///
--    /// # Panics
--    /// This method will panic if result is not finite, negative or overflows `Duration`.
--    ///
--    /// # Examples
--    /// ```
--    /// #![feature(duration_float)]
--    /// use std::time::Duration;
--    ///
--    /// let dur = Duration::new(2, 700_000_000);
--    /// // note that due to rounding errors result is slightly
--    /// // different from 0.859_872_611
--    /// assert_eq!(dur.div_f32(3.14), Duration::new(0, 859_872_576));
--    /// // note that truncation is used, not rounding
--    /// assert_eq!(dur.div_f32(3.14e5), Duration::new(0, 8_598));
--    /// ```
--    #[unstable(feature = "duration_float", issue = "54361")]
--    #[inline]
--    pub fn div_f32(self, rhs: f32) -> Duration {
--        Duration::from_secs_f32(self.as_secs_f32() / rhs)
--    }
--
--    /// Divide `Duration` by `Duration` and return `f64`.
--    ///
--    /// # Examples
--    /// ```
--    /// #![feature(duration_float)]
--    /// use std::time::Duration;
--    ///
--    /// let dur1 = Duration::new(2, 700_000_000);
--    /// let dur2 = Duration::new(5, 400_000_000);
--    /// assert_eq!(dur1.div_duration_f64(dur2), 0.5);
--    /// ```
--    #[unstable(feature = "duration_float", issue = "54361")]
--    #[inline]
--    pub fn div_duration_f64(self, rhs: Duration) -> f64 {
--        self.as_secs_f64() / rhs.as_secs_f64()
--    }
--
--    /// Divide `Duration` by `Duration` and return `f32`.
--    ///
--    /// # Examples
--    /// ```
--    /// #![feature(duration_float)]
--    /// use std::time::Duration;
--    ///
--    /// let dur1 = Duration::new(2, 700_000_000);
--    /// let dur2 = Duration::new(5, 400_000_000);
--    /// assert_eq!(dur1.div_duration_f32(dur2), 0.5);
--    /// ```
--    #[unstable(feature = "duration_float", issue = "54361")]
--    #[inline]
--    pub fn div_duration_f32(self, rhs: Duration) -> f32 {
--        self.as_secs_f32() / rhs.as_secs_f32()
--    }
- }
- 
- #[stable(feature = "duration", since = "1.3.0")]
 diff --git a/src/libstd/num.rs b/src/libstd/num.rs
 index 828d572..bc04fb1 100644
 --- a/src/libstd/num.rs