Add a description for openmp-task-based-target pass

Author: bhandarkar-pranav

mlir/include/mlir/Dialect/OpenMP/Passes.td

@@ -16,7 +16,37 @@ def OpenMPTaskBasedTarget : Pass<"openmp-task-based-target", "func::FuncOp"> {
 
   let constructor = "mlir::createOpenMPTaskBasedTargetPass()";
 
-  let description = [{ First pass attempt}];
+  let description = [{
+  This pass transforms `omp.target`, `omp.target_enter_data`,
+  `omp.target_update_data` and `omp.target_exit_data` whenever these operations
+  have the `depend` clause on them.
+
+  These operations are transformed by enclosing them inside a new `omp.task`
+  operation. The `depend` clause related arguments are moved to the new `omp.task`
+  operation from the original 'target' operation.
+
+  Example:
+  Input:
+  ```mlir
+  omp.target map_entries(%map_a -> %arg0, %map_c_from -> %arg1 : memref<?xi32>, memref<?xi32>) depend(taskdependout -> %c : memref<?xi32>) {
+    ^bb0(%arg0 : memref<?xi32>, %arg1 : memref<?xi32>) :
+        "test.foobar"() : ()->()
+         omp.terminator
+  }
+  ```
+  Output:
+  ```mlir
+  omp.task depend(taskdependout -> %c : memref<?xi32>) {
+    omp.target map_entries(%map_a -> %arg0, %map_c_from -> %arg1 : memref<?xi32>, memref<?xi32>) {
+      ^bb0(%arg0 : memref<?xi32>, %arg1 : memref<?xi32>) :
+          "test.foobar"() : ()->()
+           omp.terminator
+    }
+  }
+  ```
+  The intent is to make it easier to translate to LLVMIR by avoiding the
+  creation of such tasks in the OMPIRBuilder
+  }];
 
   let dependentDialects = ["omp::OpenMPDialect"];
 }