[OpenMP] Codegen support for 'target teams' on the host.

This patch adds support for codegen of 'target teams' on the host.
This combined directive has two captured statements, one for the
'teams' region, and the other for the 'parallel'.

This target teams region is offloaded using the __tgt_target_teams()
call. The patch sets the number of teams as an argument to
this call.

Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D29084

llvm-svn: 293005
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 7db72dd..82ab5c3 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -2711,6 +2711,9 @@
   static void
   EmitOMPTargetParallelDeviceFunction(CodeGenModule &CGM, StringRef ParentName,
                                       const OMPTargetParallelDirective &S);
+  static void
+  EmitOMPTargetTeamsDeviceFunction(CodeGenModule &CGM, StringRef ParentName,
+                                   const OMPTargetTeamsDirective &S);
   /// \brief Emit inner loop of the worksharing/simd construct.
   ///
   /// \param S Directive, for which the inner loop must be emitted.