[OpenMP] Parsing + sema for target parallel directive.

Summary:
This patch adds parsing + sema for the target parallel directive and its clauses along with testcases.

Reviewers: ABataev

Differential Revision: http://reviews.llvm.org/D16553

Rebased to current trunk and updated test cases.

llvm-svn: 258832
diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index bd4fa8b..3a22a39 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -262,6 +262,9 @@
   case Stmt::OMPTargetExitDataDirectiveClass:
     EmitOMPTargetExitDataDirective(cast<OMPTargetExitDataDirective>(*S));
     break;
+  case Stmt::OMPTargetParallelDirectiveClass:
+    EmitOMPTargetParallelDirective(cast<OMPTargetParallelDirective>(*S));
+    break;
   case Stmt::OMPTaskLoopDirectiveClass:
     EmitOMPTaskLoopDirective(cast<OMPTaskLoopDirective>(*S));
     break;