[Flang][OpenMP] Implement workdistribute construct lowering

flang/include/flang/Optimizer/OpenMP/Passes.td

@@ -93,6 +93,10 @@ def LowerWorkshare : Pass<"lower-workshare", "::mlir::ModuleOp"> {
   let summary = "Lower workshare construct";
 }
 
+def LowerWorkdistribute : Pass<"lower-workdistribute", "::mlir::ModuleOp"> {
+  let summary = "Lower workdistribute construct";
+}
+
 def GenericLoopConversionPass
     : Pass<"omp-generic-loop-conversion", "mlir::func::FuncOp"> {
   let summary = "Converts OpenMP generic `omp.loop` to semantically "

flang/lib/Optimizer/OpenMP/CMakeLists.txt

@@ -8,6 +8,7 @@ add_flang_library(FlangOpenMPTransforms
   MapsForPrivatizedSymbols.cpp
   MapInfoFinalization.cpp
   MarkDeclareTarget.cpp
+  LowerWorkdistribute.cpp
   LowerWorkshare.cpp
   LowerNontemporal.cpp
   SimdOnly.cpp