Fix some SIMD intrinsics documentation

Author: meesfrensel

core/src/intrinsics/simd.rs

@@ -152,15 +152,15 @@ extern "rust-intrinsic" {
     #[rustc_nounwind]
     pub fn simd_fabs<T>(x: T) -> T;
 
-    /// Elementwise minimum of a vector.
+    /// Elementwise minimum of two vectors.
     ///
     /// `T` must be a vector of floating-point primitive types.
     ///
     /// Follows IEEE-754 `minNum` semantics.
     #[rustc_nounwind]
     pub fn simd_fmin<T>(x: T, y: T) -> T;
 
-    /// Elementwise maximum of a vector.
+    /// Elementwise maximum of two vectors.
     ///
     /// `T` must be a vector of floating-point primitive types.
     ///
@@ -387,7 +387,7 @@ extern "rust-intrinsic" {
     #[rustc_nounwind]
     pub fn simd_reduce_mul_ordered<T, U>(x: T, y: U) -> U;
 
-    /// Add elements within a vector in arbitrary order. May also be re-associated with
+    /// Multiply elements within a vector in arbitrary order. May also be re-associated with
     /// unordered additions on the inputs/outputs.
     ///
     /// `T` must be a vector of integer or floating-point primitive types.
@@ -405,7 +405,7 @@ extern "rust-intrinsic" {
     #[rustc_nounwind]
     pub fn simd_reduce_all<T>(x: T) -> bool;
 
-    /// Check if all mask values are true.
+    /// Check if any mask value is true.
     ///
     /// `T` must be a vector of integer primitive types.
     ///