mlir/tblgen test: add a test for EnumAttr customAssemblyFormat

[artagnon]

Summary

attr-or-type-format.td contains tests for various attributes and types,
but nowhere in the testsuite is the customAssemblyFormat for an EnumAttr
(enum class in C++) exercised. Fix this by adding a test.

Signed-off-by: Ramkumar Ramachandra <[e-mail]>

mlir/test/mlir-tblgen/attr-or-type-format.td

 // RUN: mlir-tblgen -gen-attrdef-defs -I %S/../../include %s | FileCheck %s --check-prefix=ATTR
 // RUN: mlir-tblgen -gen-typedef-defs -I %S/../../include %s | FileCheck %s --check-prefix=TYPE
 
 include "mlir/IR/AttrTypeBase.td"
+include "mlir/IR/EnumAttr.td"
 include "mlir/IR/OpBase.td"
 
 /// Test that attribute and type printers and parsers are correctly generated.
 def Test_Dialect : Dialect {
   let name = "TestDialect";
   let cppNamespace = "::test";
   let useDefaultTypePrinterParser = 0;
 }

 // ATTR-NEXT: getType()
 
 def AttrE : TestAttr<"TestH"> {
   let parameters = (ins AttributeSelfTypeParameter<"">:$type);
   let mnemonic = "attr_e";
   let assemblyFormat = "custom<UseType>(ref($type))";
 }
 
+def TestEnum : I32EnumAttr<"TestEnum", "TestEnumType", [
+  I32EnumAttrCase<"first", 0>,
+  I32EnumAttrCase<"second", 1>
+]> {
+  let genSpecializedAttr = 0;
+}
+
+// ATTR-LABEL: TestEnumAttr::parse
+// ATTR: parseFoo(odsParser,
+// ATTR-NEXT: _result_value
+// ATTR-LABEL: TestEnumAttr::print
+// ATTR: printFoo(odsPrinter,
+// ATTR-NEXT: getValue()
+def EnumAttrA : EnumAttr<Test_Dialect, TestEnum, "EnumAttrA"> {
+  let assemblyFormat = "custom<Foo>($value)";
+}
+
 /// Test type parser and printer that mix variables and struct are generated
 /// correctly.
 
 // TYPE: ::mlir::Type TestCType::parse(::mlir::AsmParser &odsParser) {
 // TYPE:  FailureOr<IntegerAttr> _result_value;
 // TYPE:  FailureOr<TestParamC> _result_complex;
 // TYPE:  if (odsParser.parseKeyword("foo"))
 // TYPE:    return {};