[OPENMP 4.1] Initial support for modifiers in 'linear' clause.

OpenMP 4.1 adds 3 optional modifiers to 'linear' clause.
Format of 'linear' clause has changed to:
```
linear(linear-list[ : linear-step])
```
where linear-list is one of the following
```
list
modifier(list)
```
where modifier is one of the following:
```
 ref (C++)
 val (C/C++)
 uval (C++)
```
Patch adds parsing and sema analysis for these modifiers.

llvm-svn: 245550

1 files changed, 6 insertions, 0 deletions

diff --git a/clang/lib/AST/StmtPrinter.cpp b/clang/lib/AST/StmtPrinter.cpp
index 64f90ba951d..fb5fcc4902d 100644
--- a/clang/lib/AST/StmtPrinter.cpp
+++ b/clang/lib/AST/StmtPrinter.cpp
@@ -767,7 +767,13 @@ void OMPClausePrinter::VisitOMPReductionClause(OMPReductionClause *Node) {
 void OMPClausePrinter::VisitOMPLinearClause(OMPLinearClause *Node) {
   if (!Node->varlist_empty()) {
     OS << "linear";
+    if (Node->getModifierLoc().isValid()) {
+      OS << '('
+         << getOpenMPSimpleClauseTypeName(OMPC_linear, Node->getModifier());
+    }
     VisitOMPClauseList(Node, '(');
+    if (Node->getModifierLoc().isValid())
+      OS << ')';
     if (Node->getStep() != nullptr) {
       OS << ": ";
       Node->getStep()->printPretty(OS, nullptr, Policy, 0);