Don't use compile_error!

Also, update the docs attrube to point to both relevant features.

Signed-off-by: Joe Richey <joerichey@google.com>

Author: josephlr

src/instructions/interrupts.rs

@@ -152,14 +152,11 @@ pub fn int3() {
 /// This currently needs to be a macro because the `int` argument needs to be an
 /// immediate. This macro will be replaced by a generic function when support for
 /// const generics is implemented in Rust.
-#[cfg_attr(docsrs, doc(cfg(feature = "nightly")))]
+#[cfg(feature = "inline_asm")]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "nightly", feature = "inline_asm"))))]
 #[macro_export]
 macro_rules! software_interrupt {
     ($x:expr) => {{
-        #[cfg(feature = "inline_asm")]
         asm!("int {id}", id = const $x, options(nomem, nostack));
-
-        #[cfg(not(feature = "inline_asm"))]
-        compile_error!("software_interrupt!() requires \"nightly\" feature");
     }};
 }

src/instructions/mod.rs

@@ -53,16 +53,13 @@ pub fn bochs_breakpoint() {
 
 /// Gets the current instruction pointer. Note that this is only approximate as it requires a few
 /// instructions to execute.
-#[cfg_attr(docsrs, doc(cfg(feature = "nightly")))]
+#[cfg(feature = "inline_asm")]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "nightly", feature = "inline_asm"))))]
 #[inline(always)]
 pub fn read_rip() -> crate::VirtAddr {
     let rip: u64;
-    #[cfg(feature = "inline_asm")]
     unsafe {
         asm!("lea {}, [rip]", out(reg) rip, options(nostack, nomem, preserves_flags));
     }
-
-    #[cfg(not(feature = "inline_asm"))]
-    compile_error!("read_rip() requires \"nightly\" feature");
     crate::VirtAddr::new(rip)
 }