Fix MLIR standalone example to properly handle namespace

ODS TableGen backend now requires to spell out which namespace they have
to be nested in, in an absolute way.

mlir/examples/standalone/include/Standalone/StandaloneDialect.h

@@ -11,12 +11,6 @@
 
 #include "mlir/IR/Dialect.h"
 
-namespace mlir {
-namespace standalone {
-
 #include "Standalone/StandaloneOpsDialect.h.inc"
 
-} // namespace standalone
-} // namespace mlir
-
 #endif // STANDALONE_STANDALONEDIALECT_H

mlir/examples/standalone/include/Standalone/StandaloneDialect.td

@@ -23,7 +23,7 @@ def Standalone_Dialect : Dialect {
         illustrate the basic setup required to develop MLIR-based tools without
         working inside of the LLVM source tree.
     }];
-    let cppNamespace = "standalone";
+    let cppNamespace = "::mlir::standalone";
 }
 
 //===----------------------------------------------------------------------===//

mlir/examples/standalone/include/Standalone/StandaloneOps.h

@@ -13,13 +13,7 @@
 #include "mlir/IR/OpDefinition.h"
 #include "mlir/Interfaces/SideEffectInterfaces.h"
 
-namespace mlir {
-namespace standalone {
-
 #define GET_OP_CLASSES
 #include "Standalone/StandaloneOps.h.inc"
 
-} // namespace standalone
-} // namespace mlir
-
 #endif // STANDALONE_STANDALONEOPS_H

mlir/examples/standalone/lib/Standalone/StandaloneOps.cpp

@@ -10,9 +10,5 @@
 #include "Standalone/StandaloneDialect.h"
 #include "mlir/IR/OpImplementation.h"
 
-namespace mlir {
-namespace standalone {
 #define GET_OP_CLASSES
 #include "Standalone/StandaloneOps.cpp.inc"
-} // namespace standalone
-} // namespace mlir