Fixes #642 Remove redundant non-cortex-m stub for interrupt::free

cortex-m/CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Removed
+- The separate `#[cfg(not(cortex_m))]` stub for `interrupt::free`. The real
+  `free` already compiles on non-Cortex-M targets on its own (it only calls
+  functions that fall back to `unimplemented!()` off-target), so the stub was
+  dead weight.
+
 ### Fixed
 - `NVIC`'s interrupt-bitmap accessors no longer emit a bounds check and a panic
   path.

cortex-m/src/interrupt.rs

@@ -64,7 +64,6 @@ pub unsafe fn enable() {
 /// Execute closure `f` in an interrupt-free context.
 ///
 /// This as also known as a "critical section".
-#[cfg(cortex_m)]
 #[inline]
 pub fn free<F, R>(f: F) -> R
 where
@@ -86,17 +85,3 @@ where
 
     r
 }
-
-// Make a `free()` function available on hosted platforms to allow checking dependencies without
-// specifying a target, but that will panic at runtime if executed.
-/// Execute closure `f` in an interrupt-free context.
-///
-/// This as also known as a "critical section".
-#[cfg(not(cortex_m))]
-#[inline]
-pub fn free<F, R>(_: F) -> R
-where
-    F: FnOnce(&CriticalSection) -> R,
-{
-    panic!("cortex_m::interrupt::free() is only functional on cortex-m platforms");
-}