added basic dataflow analysis to skslc

src/sksl/ir/SkSLVarDeclarationStatement.h

-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
- 
-#ifndef SKSL_VARDECLARATIONSTATEMENT
-#define SKSL_VARDECLARATIONSTATEMENT
-
-#include "SkSLStatement.h"
-#include "SkSLVarDeclaration.h"
-
-namespace SkSL {
-
-/**
- * One or more variable declarations appearing as a statement within a function.
- */
-struct VarDeclarationsStatement : public Statement {
-    VarDeclarationsStatement(std::unique_ptr<VarDeclarations> decl)
-    : INHERITED(decl->fPosition, kVarDeclarations_Kind) 
-    , fDeclaration(std::move(decl)) {}
-
-    std::string description() const override {
-        return fDeclaration->description();
-    }
-
-    const std::shared_ptr<VarDeclarations> fDeclaration;
-
-    typedef Statement INHERITED;
-};
-
-} // namespace
-
-#endif