add dart-scheduler simple filecheck

The scheduler is tested quite rigorously in pytests, this filecheck just
makes sure that the pass applying the scheduler works correctly

tests/filecheck/transforms/dart/dart-scheduler.mlir

@@ -0,0 +1,25 @@
+// RUN: ./compiler/snax-opt --split-input-file %s -p insert-accfg-op{accelerator=snax_gemmx},dart-scheduler | filecheck %s
+
+func.func @streamer_matmul(%arg0 : memref<16x16xi8>, %arg1 : memref<16x16xi8, strided<[1, 16]>>, %arg2 : memref<16x16xi32>) {
+  %0 = arith.constant 0 : i32
+  "dart.operation"(%arg0, %arg1, %arg2) <{patterns = [affine_map<(d0, d1, d2) -> (d0, d2)>, affine_map<(d0, d1, d2) -> (d2, d1)>, affine_map<(d0, d1, d2) -> (d0, d1)>], accelerator = "snax_gemmx", operandSegmentSizes = array<i32: 2, 1>}> ({
+  ^0(%1 : !dart.stream<i8>, %2 : !dart.stream<i8>, %3 : !dart.stream<i32>):
+    %4 = "dart.generic"(%1, %2, %0, %0) <{library_call = "snax_gemmx"}> ({
+    ^1(%arg3 : i8, %arg4 : i8, %arg5 : i32, %arg6 : i32, %arg7 : i32):
+      %5 = kernel.qmac %arg3, %arg4 zp_lhs : %arg5 zp_rhs : %arg6 : i8, i8, i32, i32 -> i32
+      dart.yield %5 : i32
+    }) : (!dart.stream<i8>, !dart.stream<i8>, i32, i32) -> !dart.stream<i32>
+    dart.yield %4 : !dart.stream<i32>
+  }) : (memref<16x16xi8>, memref<16x16xi8, strided<[1, 16]>>, memref<16x16xi32>) -> ()
+  func.return
+}
+
+// CHECK:     "dart.schedule"(%arg0, %arg1, %arg2) <{patterns = [affine_map<(d0, d1, d2, d3, d4, d5) -> (((d0 * 8) + d3), ((d2 * 8) + d5))>, affine_map<(d0, d1, d2, d3, d4, d5) -> (((d2 * 8) + d5), ((d1 * 8) + d4))>, affine_map<(d0, d1, d2, d3, d4, d5) -> (((d0 * 8) + d3), ((d1 * 8) + d4))>], accelerator = "snax_gemmx", tiles = [[]], bounds = [2 : index, 2 : index, 2 : index, 8 : index, 8 : index, 8 : index], operandSegmentSizes = array<i32: 2, 1>}> ({
+// CHECK-NEXT:     ^0(%1 : !dart.stream<i8>, %2 : !dart.stream<i8>, %3 : !dart.stream<i32>):
+// CHECK-NEXT:       %4 = "dart.generic"(%1, %2, %0, %0) <{library_call = "snax_gemmx"}> ({
+// CHECK-NEXT:       ^1(%arg3 : i8, %arg4 : i8, %arg5 : i32, %arg6 : i32, %arg7 : i32):
+// CHECK-NEXT:         %5 = kernel.qmac %arg3, %arg4 zp_lhs : %arg5 zp_rhs : %arg6 : i8, i8, i32, i32 -> i32
+// CHECK-NEXT:         dart.yield %5 : i32
+// CHECK-NEXT:       }) : (!dart.stream<i8>, !dart.stream<i8>, i32, i32) -> !dart.stream<i32>
+// CHECK-NEXT:       dart.yield %4 : !dart.stream<i32>
+// CHECK-NEXT:     }) : (memref<16x16xi8>, memref<16x16xi8, strided<[1, 16]>>, memref<16x16xi32>) -> ()