[OpenMP][MLIR] Add assembly format for master op

[kiranchandramohan]

Summary

Adding assembly format for master op.

[SouraVX]

Thanks @kiranchandramohan for pushing this separately.
LGTM :)

[SouraVX]

mlir/test/Dialect/OpenMP/ops.mlir

9

Nit: You may choose to remove this generic format test case.

[kiranktp]

LGTM

[SouraVX]

Reverse Ping! Could you please land this ?

[kiranchandramohan]

Removing generic syntax tests before submitting as suggested by @SouraVX.

mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td

 def MasterOp : OpenMP_Op<"master"> {
   let summary = "master construct";
   let description = [{
     The master construct specifies a structured block that is executed by
     the master thread of the team.
   }];
 
   let regions = (region AnyRegion:$region);
+
+  let assemblyFormat = "$region attr-dict";
 }
 
 //===----------------------------------------------------------------------===//
 // 2.17.2 barrier Construct
 //===----------------------------------------------------------------------===//
 
 def BarrierOp : OpenMP_Op<"barrier"> {
   let summary = "barrier construct";

mlir/test/Dialect/OpenMP/ops.mlir

 // RUN: mlir-opt %s | mlir-opt | FileCheck %s
 
 func @omp_barrier() -> () {
   // CHECK: omp.barrier
   omp.barrier
   return
 }
 
 func @omp_master() -> () {
   // CHECK: omp.master
   "omp.master" ()({
     // CHECK: omp.terminator
     omp.terminator
   }):()->()
+
+  // CHECK: omp.master
+  omp.master {
+    // CHECK: omp.terminator
+    omp.terminator
+  }
+
   return
 }
 
 func @omp_taskwait() -> () {
   // CHECK: omp.taskwait
   omp.taskwait
   return
 }