Change f16 doctests in core to run on x86-64

Since `f16` now works on x86 and x86-64, change doctests to use this
instead of aarch64. This is to make sure any changes get run in PR CI.

Author: tgross35

library/core/src/num/f16.rs

@@ -267,7 +267,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let nan = f16::NAN;
     /// let f = 7.0_f16;
@@ -301,7 +301,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let f = 7.0f16;
     /// let inf = f16::INFINITY;
@@ -328,7 +328,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let f = 7.0f16;
     /// let inf: f16 = f16::INFINITY;
@@ -357,7 +357,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let min = f16::MIN_POSITIVE; // 6.1035e-5
     /// let max = f16::MAX;
@@ -388,7 +388,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let min = f16::MIN_POSITIVE; // 6.1035e-5
     /// let max = f16::MAX;
@@ -421,7 +421,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// use std::num::FpCategory;
     ///
@@ -744,7 +744,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let value = 4.6_f16;
     /// let rounded = unsafe { value.to_int_unchecked::<u16>() };
@@ -787,7 +787,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// # // FIXME(f16_f128): enable this once const casting works
     /// # // assert_ne!((1f16).to_bits(), 1f16 as u128); // to_bits() is not casting!
@@ -876,7 +876,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let v = f16::from_bits(0x4a40);
     /// assert_eq!(v, 12.5);
@@ -1030,7 +1030,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let value = f16::from_be_bytes([0x4a, 0x40]);
     /// assert_eq!(value, 12.5);
@@ -1053,7 +1053,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let value = f16::from_le_bytes([0x40, 0x4a]);
     /// assert_eq!(value, 12.5);
@@ -1083,7 +1083,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let value = f16::from_ne_bytes(if cfg!(target_endian = "big") {
     ///     [0x4a, 0x40]
@@ -1217,7 +1217,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// assert!((-3.0f16).clamp(-2.0, 1.0) == -2.0);
     /// assert!((0.0f16).clamp(-2.0, 1.0) == 0.0);