acle: move saturating intrinsics into its own module

addresses #557 (comment)

Author: japaric

crates/core_arch/src/acle/dsp.rs

@@ -1,7 +1,6 @@
 //! # References:
 //!
 //! - Section 8.3 "16-bit multiplications"
-//! - Section 8.4 "Saturating intrinsics"
 //!
 //! Intrinsics that could live here:
 //!
@@ -11,8 +10,6 @@
 //! - __smultt
 //! - __smulwb
 //! - __smulwt
-//! - __ssat
-//! - __usat
 //! - __qadd
 //! - __qsub
 //! - __qdbl

crates/core_arch/src/acle/mod.rs

@@ -79,6 +79,19 @@ mod dsp;
 ))]
 pub use self::dsp::*;
 
+// Supported arches: 6, 7-M. See Section 10.1 of ACLE (e.g. SSAT)
+#[cfg(all(
+    not(target_arch = "aarch64"),
+    target_feature = "v6",
+))]
+mod sat;
+
+#[cfg(all(
+    not(target_arch = "aarch64"),
+    target_feature = "v6",
+))]
+pub use self::sat::*;
+
 // Deprecated in ACLE 2.0 for the A profile but fully supported on the M and R profiles, says
 // Section 5.4.9 of ACLE. We'll expose these for the A profile even if deprecated
 #[cfg(all(

crates/core_arch/src/acle/sat.rs

@@ -0,0 +1,8 @@
+//! # References:
+//!
+//! - Section 8.4 "Saturating intrinsics"
+//!
+//! Intrinsics that could live here:
+//!
+//! - __ssat
+//! - __usat