[OPENMP50]Add basic support for array-shaping operation.

Summary:
Added basic representation and parsing/sema handling of array-shaping
operations. Array shaping expression is an expression of form ([s0]..[sn])base,
where s0, ..., sn must be a positive integer, base - a pointer. This
expression is a kind of cast operation that converts pointer expression
into an array-like kind of expression.

Reviewers: rjmccall, rsmith, jdoerfert

Subscribers: guansong, arphaman, cfe-commits, caomhin, kkwli0

Tags: #clang

Differential Revision: https://reviews.llvm.org/D74144
diff --git a/clang/lib/AST/NSAPI.cpp b/clang/lib/AST/NSAPI.cpp
index ae6ff04..2bfe977 100644
--- a/clang/lib/AST/NSAPI.cpp
+++ b/clang/lib/AST/NSAPI.cpp
@@ -483,6 +483,7 @@
   case BuiltinType::PseudoObject:
   case BuiltinType::BuiltinFn:
   case BuiltinType::OMPArraySection:
+  case BuiltinType::OMPArrayShaping:
     break;
   }