Fix formatting of doc comment

Author: chorman0773

library/core/src/arch.rs

@@ -80,13 +80,17 @@ pub fn breakpoint() {
 /// The `core::arch::return_address!()` macro returns a pointer with an address that corresponds to the caller of the function that invoked the `return_address!()` macro.
 /// The pointer has no provenance, as if created by `core::ptr::without_provenance`. It cannot be used to read memory (other than ZSTs).
 ///
-/// The value returned by the macro depends highly on the architecture and compiler (including any options set). 
-/// In particular, it is allowed to be wrong (particularly if inlining is involved), or even contain a nonsense value. 
+/// The value returned by the macro depends highly on the architecture and compiler (including any options set).
+/// In particular, it is allowed to be wrong (particularly if inlining is involved), or even contain a nonsense value.
 /// The result of this macro must not be relied upon for soundness or correctness, only for debugging purposes.
+///
+/// As a best effort, if a useful value cannot be determined (for example, due to limitations on the current codegen),
+/// this macro tries to return a null pointer instead of nonsense (this cannot be relied upon for correctness, however).
+///
 /// Formally, this function returns a pointer with a non-deterministic address and no provenance.
-/// As a best effort, if a useful value cannot be determined (for example, due to limitations on the current codegen), this macro tries to return a null pointer instead of nonsense (this cannot be relied upon for correctness, however).
 ///
-/// This is equivalent to the gcc `__builtin_return_address(0)` intrinsic (other forms of the intrinsic are not supported). Because the operation can be always performed by the compiler without crashing or causing undefined behaviour, invoking the macro is a safe operation.
+/// This is equivalent to the gcc `__builtin_return_address(0)` intrinsic (other forms of the intrinsic are not supported).
+/// Because the operation can be always performed by the compiler without crashing or causing undefined behaviour, invoking the macro is a safe operation.
 ///
 /// ## Example
 /// ```