[mlir] Add `parseSymbolName` that doesn't take an attribute list

[Mogball]

Summary

This patch adds a version of parseSymbolName and
parseOptionalSymbolName to AsmParser that don't take an attribute name
and attribute list.

[rriddle]

Much nicer!

mlir/include/mlir/IR/OpImplementation.h

public:
   /// Parse an integer set instance into 'set'.
   virtual ParseResult printIntegerSet(IntegerSet &set) = 0;
 
   //===--------------------------------------------------------------------===//
   // Identifier Parsing
   //===--------------------------------------------------------------------===//
 
   /// Parse an @-identifier and store it (without the '@' symbol) in a string
+  /// attribute.
+  ParseResult parseSymbolName(StringAttr &result) {
+    if (failed(parseOptionalSymbolName(result)))
+      return emitError(getCurrentLocation())
+             << "expected valid '@'-identifier for symbol name";
+    return success();
+  }
+
+  /// Parse an @-identifier and store it (without the '@' symbol) in a string
   /// attribute named 'attrName'.
   ParseResult parseSymbolName(StringAttr &result, StringRef attrName,
                               NamedAttrList &attrs) {
-    if (failed(parseOptionalSymbolName(result, attrName, attrs)))
-      return emitError(getCurrentLocation())
-             << "expected valid '@'-identifier for symbol name";
+    if (parseSymbolName(result))
+      return failure();
+    attrs.append(attrName, result);
     return success();
   }
 
   /// Parse an optional @-identifier and store it (without the '@' symbol) in a
+  /// string attribute.
+  virtual ParseResult parseOptionalSymbolName(StringAttr &result) = 0;
+
+  /// Parse an optional @-identifier and store it (without the '@' symbol) in a
   /// string attribute named 'attrName'.
-  virtual ParseResult parseOptionalSymbolName(StringAttr &result,
-                                              StringRef attrName,
-                                              NamedAttrList &attrs) = 0;
+  ParseResult parseOptionalSymbolName(StringAttr &result, StringRef attrName,
+                                      NamedAttrList &attrs) {
+    if (succeeded(parseOptionalSymbolName(result))) {
+      attrs.append(attrName, result);
+      return success();
+    }
+    return failure();
+  }
 
   //===--------------------------------------------------------------------===//
   // Resource Parsing
   //===--------------------------------------------------------------------===//
 
   /// Parse a handle to a resource within the assembly format.
   template <typename ResourceT>
   FailureOr<ResourceT> parseResourceHandle() {

mlir/lib/AsmParser/AsmParserImpl.h

public:
   }
 
   //===--------------------------------------------------------------------===//
   // Identifier Parsing
   //===--------------------------------------------------------------------===//
 
   /// Parse an optional @-identifier and store it (without the '@' symbol) in a
   /// string attribute named 'attrName'.
-  ParseResult parseOptionalSymbolName(StringAttr &result, StringRef attrName,
-                                      NamedAttrList &attrs) override {
+  ParseResult parseOptionalSymbolName(StringAttr &result) override {
     Token atToken = parser.getToken();
     if (atToken.isNot(Token::at_identifier))
       return failure();
 
     result = getBuilder().getStringAttr(atToken.getSymbolReference());
-    attrs.push_back(getBuilder().getNamedAttr(attrName, result));
     parser.consumeToken();
 
     // If we are populating the assembly parser state, record this as a symbol
     // reference.
     if (parser.getState().asmState) {
       parser.getState().asmState->addUses(SymbolRefAttr::get(result),
                                           atToken.getLocRange());
     }