[OPNEMP]Allow num_tasks clause in combined task-based directives.

The expression of the num_tasks clause must be captured in the combined
task-based directives, like 'parallel master taskloop' directive.

llvm-svn: 374819
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 57c9242..3badff4 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -6944,6 +6944,7 @@
 }
 
 void OMPClauseWriter::VisitOMPNumTasksClause(OMPNumTasksClause *C) {
+  VisitOMPClauseWithPreInit(C);
   Record.AddStmt(C->getNumTasks());
   Record.AddSourceLocation(C->getLParenLoc());
 }