[OPENMP] Codegen for 'reduction' clause in 'parallel' directive.

Emit a code for reduction clause. Next code should be emitted for reductions:

static kmp_critical_name lock = { 0 };

void reduce_func(void *lhs[<n>], void *rhs[<n>]) {
  ...
  *(Type<i> *)lhs[i] = RedOp<i>(*(Type<i> *)lhs[i], *(Type<i> *)rhs[i]);
  ...
}

... void *RedList[<n>] = {&<RHSExprs>[0], ..., &<RHSExprs>[<n> - 1]};
switch (__kmpc_reduce{_nowait}(<loc>, <gtid>, <n>, sizeof(RedList), RedList, reduce_func, &<lock>)) {
case 1:
  ...
  <LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]);
  ...
  __kmpc_end_reduce{_nowait}(<loc>, <gtid>, &<lock>);
  break;
case 2:
  ...
  Atomic(<LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]));
  ...
  break;
default:
  ;
}
Reduction variables are a kind of a private variables, they have private copies, but initial values are chosen in accordance with the reduction operation.

Differential Revision: http://reviews.llvm.org/D8915

llvm-svn: 234583
diff --git a/clang/lib/AST/StmtProfile.cpp b/clang/lib/AST/StmtProfile.cpp
index f29f6a8..002a17f 100644
--- a/clang/lib/AST/StmtProfile.cpp
+++ b/clang/lib/AST/StmtProfile.cpp
@@ -356,6 +356,15 @@
       C->getQualifierLoc().getNestedNameSpecifier());
   Profiler->VisitName(C->getNameInfo().getName());
   VisitOMPClauseList(C);
+  for (auto *E : C->lhs_exprs()) {
+    Profiler->VisitStmt(E);
+  }
+  for (auto *E : C->rhs_exprs()) {
+    Profiler->VisitStmt(E);
+  }
+  for (auto *E : C->reduction_ops()) {
+    Profiler->VisitStmt(E);
+  }
 }
 void OMPClauseProfiler::VisitOMPLinearClause(const OMPLinearClause *C) {
   VisitOMPClauseList(C);