Add case for count_code_region() extern lang_item

As suggested in PR feedback:

https://github.com/rust-lang/rust/pull/73011#discussion_r435728923

This allows count_code_region() to be handled like a normal intrinsic so
the InstanceDef::InjectedCode variant is no longer needed.

1 files changed, 6 insertions, 15 deletions

diff --git a/src/libcore/intrinsics.rs b/src/libcore/intrinsics.rs
index 06a432a2696..7ce5814d39a 100644
--- a/src/libcore/intrinsics.rs
+++ b/src/libcore/intrinsics.rs
@@ -1941,22 +1941,13 @@ extern "rust-intrinsic" {
     ///
     /// Perma-unstable: do not use.
     pub fn miri_start_panic(payload: *mut u8) -> !;
-}
 
-/// Defines the `count_code_region` intrinsic as a `LangItem`. `LangItem`s require a function body
-/// to register its DefId with the LangItem entry. The function body is never actually called (and
-/// is therefore implemented as an aborting stub) because it is replaced with the LLVM intrinsic
-/// `llvm.instrprof.increment` by
-/// `rustc_codegen_llvm::intrinsic::IntrinsicCallMethods::codegen_intrinsic_call()`.
-#[cfg(not(bootstrap))]
-#[cfg_attr(not(bootstrap), lang = "count_code_region")]
-fn count_code_region(_index: u32) {
-    // remove `unsafe` (and safety comment) on bootstrap bump
-    #[cfg_attr(not(bootstrap), allow(unused_unsafe))]
-    // SAFETY: the `abort` intrinsic has no requirements to be called.
-    unsafe {
-        abort()
-    }
+    /// Internal placeholder for injecting code coverage counters when the "instrument-coverage"
+    /// option is enabled. The placeholder is replaced with `llvm.instrprof.increment` during code
+    /// generation.
+    #[cfg(not(bootstrap))]
+    #[cfg_attr(not(bootstrap), lang = "count_code_region")]
+    pub fn count_code_region(_index: u32);
 }
 
 // Some functions are defined here because they accidentally got made