[mlir] NFC: tiny fix in comment.

[csigg]

Add another one.

[mehdi_amini]

(Feel free to just push directly this kind of fixes)

mlir/include/mlir/IR/StandardTypes.h

 /// or dynamic (encoded with getDynamicStrideOrOffset()). Strides encode the
 /// distance in the number of elements between successive entries along a
 /// particular dimension. For example, `memref<42x16xf32, (64 * d0 + d1)>`
 /// specifies a view into a non-contiguous memory region of `42` by `16` `f32`
 /// elements in which the distance between two consecutive elements along the
 /// outer dimension is `1` and the distance between two consecutive elements
 /// along the inner dimension is `64`.
 ///
-/// If a simple strided form cannot be extracted from the composition of the
-/// layout map, returns llvm::None.
+/// Returns whether a simple strided form can be extracted from the composition
+/// of the layout map.
 ///
 /// The convention is that the strides for dimensions d0, .. dn appear in
 /// order to make indexing intuitive into the result.
 LogicalResult getStridesAndOffset(MemRefType t,
                                   SmallVectorImpl<int64_t> &strides,
                                   int64_t &offset);
 LogicalResult getStridesAndOffset(MemRefType t,
                                   SmallVectorImpl<AffineExpr> &strides,

mlir/include/mlir/IR/Types.h

public:
 
   // Support type casting Type to itself.
   static bool classof(Type) { return true; }
 
   /// Return a unique identifier for the concrete type. This is used to support
   /// dynamic type casting.
   TypeID getTypeID() { return impl->getAbstractType().getTypeID(); }
 
-  /// Return the LLVMContext in which this type was uniqued.
+  /// Return the MLIRContext in which this type was uniqued.
   MLIRContext *getContext() const;
 
   /// Get the dialect this type is registered to.
   Dialect &getDialect() const;
 
   // Convenience predicates.  This is only for floating point types,
   // derived types should use isa/dyn_cast.
   bool isIndex();