Fix attr aliasing on region args (#389)

* Fix for aliasing the region args

* Add test case

* Add empty line

Author: josel-amd

mlir/lib/IR/AsmPrinter.cpp

@@ -779,6 +779,7 @@ class DummyAliasOperationPrinter : private OpAsmPrinter {
   void printRegionArgument(BlockArgument arg, ArrayRef<NamedAttribute> argAttrs,
                            bool omitType) override {
     printType(arg.getType());
+    printOptionalAttrDict(argAttrs);
     // Visit the argument location.
     if (printerFlags.shouldPrintDebugInfo())
       // TODO: Allow deferring argument locations.

mlir/test/IR/test-region-attr-aliasing.mlir

@@ -0,0 +1,11 @@
+// RUN: mlir-opt %s | FileCheck %s
+
+#map = affine_map<(d0) -> (d0)>
+// CHECK: {builtin.test = #map}
+func.func @test_attr_alias_on_region_attr(%arg0: memref<2xf32> {builtin.test = #map}) {
+  %c0 = arith.constant 0 : index
+  %c1 = arith.constant 0 : index
+  %2 = memref.load %arg0[%c0] : memref<2xf32>
+  memref.store %2, %arg0[%c1] : memref<2xf32>
+  return
+}