[mlir][linalg] Delete unused vars if there are shaped-only operands.

mlir/test/mlir-linalg-ods-gen/test-linalg-ods-gen.tc

def test8(A: f32(M, K), B: f32(K)) -> (C: f32(M))
   C(m) = std_subf<k>(std_mulf(A(m, k), B(k)), C(m));
 }
 
 // Test shape-only operand.
 // IMPL-LABEL:  ArrayAttr Test9Op::indexing_maps() {
 //       IMPL:    auto map0 = AffineMap::get(2, 2, {d0, d1}, context);
 //       IMPL:    auto map1 = AffineMap::get(2, 2, {d1}, context);
 //       IMPL:    auto map2 = AffineMap::get(2, 2, {d0}, context);
+// IMPL-LABEL:  void Test9Op::regionBuilder(Block &block, ValueRange captures) {
+//       IMPL:  Value [[a:.*]](args[0]), [[c:.*]](args[2]);
 ods_def<Test9Op>:
 def test9(A: f32(M, K), B: f32(K)) -> (C: f32(M))
 {
   C(m) = std_addf<k>(C(m), A(m, k));
 }

mlir/tools/mlir-linalg-ods-gen/mlir-linalg-ods-gen.cpp

 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/ToolOutputFile.h"
 
 #include <map>
+#include <set>
 
 #define DEBUG_TYPE "linalg-ods-gen"
 
 static llvm::cl::OptionCategory ODSGenCat("Linalg ODS Gen");
 
 // Commandline options
 static llvm::cl::opt<std::string>
     inputFilename(llvm::cl::Positional, llvm::cl::desc("<input file>"),
void {0}::regionBuilder(Block &block, ValueRange captures) {
     using namespace edsc;
     using namespace intrinsics;
     auto args = block.getArguments();
     Value {1};
     {2}
     (linalg_yield(ValueRange{ {3} }));
   })FMT";
 
-  unsigned idx = 0;
   std::string valueHandleStr;
   llvm::raw_string_ostream valueHandleStringStream(valueHandleStr);
-  llvm::interleaveComma(
-      llvm::seq<int>(0, state.numArgs), valueHandleStringStream, [&](auto) {
-        valueHandleStringStream << "_" << idx << "(args[" << idx << "])";
-        idx++;
-      });
+  std::set<unsigned> usedTensorId;
+  for (const auto &iter : state.orderedTensorArgs)
+    usedTensorId.insert(iter.second);
+  llvm::interleaveComma(usedTensorId, valueHandleStringStream, [&](auto idx) {
 
   std::string expressionsStr;
   llvm::raw_string_ostream expressionStringStream(expressionsStr);
   for (auto &expr : state.expressions)
     visitPostorder(*expr, [&](const Expression &e) {
       if (e.kind == Expression::Kind::TensorExpr)
         printExpr(expressionStringStream, e);
     });