[OPENMP]Add support for analysis of linear variables and step.

Summary:
Added support for basic analysis of the linear variables and linear step
expression. Linear loop iteration variables must be excluded from this
analysis, only non-loop iteration variables must be analyzed.

Reviewers: NoQ

Subscribers: guansong, cfe-commits, caomhin, kkwli0

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65461

llvm-svn: 368295
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 4b6775d..52ea1bf 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -12736,6 +12736,10 @@
   C->setFinals(Vars);
   C->setStep(Record.readSubExpr());
   C->setCalcStep(Record.readSubExpr());
+  Vars.clear();
+  for (unsigned I = 0; I != NumVars + 1; ++I)
+    Vars.push_back(Record.readSubExpr());
+  C->setUsedExprs(Vars);
 }
 
 void OMPClauseReader::VisitOMPAlignedClause(OMPAlignedClause *C) {