[TSAR, Tfm, Loop, Reversal] Fix, check that top level statement is induction variable.

Author: kaniandr

lib/Transform/Clang/LoopReversal.cpp

@@ -417,15 +417,18 @@ class ClangLoopReverseVisitor
 
 
   bool isInductionRef(clang::Stmt *S, const clang::VarDecl *Induction) {
-    do {
+    if (auto *DRE{dyn_cast<clang::DeclRefExpr>(S)};
+        DRE && DRE->getDecl() == Induction)
+      return true;
+    while (!S->children().empty()) {
       auto I(S->child_begin());
       if (++I != S->child_end())
         return false;
       S = *S->child_begin();
       if (auto *DRE{dyn_cast<clang::DeclRefExpr>(S)};
           DRE && DRE->getDecl() == Induction)
         return true;
-    } while (!S->children().empty());
+    }
     return false;
   };