[NFC] Update parseDimensionList comments for dynamic size from -1 to kDynamic

[GleasonK]

Summary

Comment is stale now that kDynamic is defined as intmin instead of -1.

Confirmed that implementation in parseDimensionListRanked uses kDynamic.

[GleasonK]

Thanks for review - will need someone with commit access land this change.

mlir/include/mlir/IR/OpImplementation.h

public:
   /// and chain through || operators.
   ParseResult addTypesToList(ArrayRef<Type> types,
                              SmallVectorImpl<Type> &result) {
     result.append(types.begin(), types.end());
     return success();
   }
 
   /// Parse a dimension list of a tensor or memref type.  This populates the
-  /// dimension list, using -1 for the `?` dimensions if `allowDynamic` is set
-  /// and errors out on `?` otherwise. Parsing the trailing `x` is configurable.
+  /// dimension list, using ShapedType::kDynamic for the `?` dimensions if
+  /// `allowDynamic` is set and errors out on `?` otherwise. Parsing the
+  /// trailing `x` is configurable.
   ///
   ///   dimension-list ::= eps | dimension (`x` dimension)*
   ///   dimension-list-with-trailing-x ::= (dimension `x`)*
   ///   dimension ::= `?` | decimal-literal
   ///
   /// When `allowDynamic` is not set, this is used to parse:
   ///
   ///   static-dimension-list ::= eps | decimal-literal (`x` decimal-literal)*

mlir/lib/AsmParser/TypeParser.cpp

if (consumeIf(Token::l_square)) {
     return emitWrongTokenError(
         "missing ']' closing set of scalable dimensions");
   }
 
   return success();
 }
 
 /// Parse a dimension list of a tensor or memref type.  This populates the
-/// dimension list, using -1 for the `?` dimensions if `allowDynamic` is set and
-/// errors out on `?` otherwise. Parsing the trailing `x` is configurable.
+/// dimension list, using ShapedType::kDynamic for the `?` dimensions if
+/// `allowDynamic` is set and errors out on `?` otherwise. Parsing the trailing
+/// `x` is configurable.
 ///
 ///   dimension-list ::= eps | dimension (`x` dimension)*
 ///   dimension-list-with-trailing-x ::= (dimension `x`)*
 ///   dimension ::= `?` | decimal-literal
 ///
 /// When `allowDynamic` is not set, this is used to parse:
 ///
 ///   static-dimension-list ::= eps | decimal-literal (`x` decimal-literal)*