Add support for do/while loops

This commit adds support for a standard do <statement> while <expr>;
form of statement.  While loops were already being supported; supporting
a do/while loop mostly involves reusing code from while loops but putting
the conditional checking last.

libsolidity/ast/AST.h

@@ -1005,18 +1005,22 @@ public:
 		SourceLocation const& _location,
 		ASTPointer<ASTString> const& _docString,
 		ASTPointer<Expression> const& _condition,
-		ASTPointer<Statement> const& _body
+		ASTPointer<Statement> const& _body,
+		bool _isDoWhile
 	):
-		BreakableStatement(_location, _docString), m_condition(_condition), m_body(_body) {}
+		BreakableStatement(_location, _docString), m_condition(_condition), m_body(_body),
+		m_isDoWhile(_isDoWhile) {}
 	virtual void accept(ASTVisitor& _visitor) override;
 	virtual void accept(ASTConstVisitor& _visitor) const override;
 
 	Expression const& condition() const { return *m_condition; }
 	Statement const& body() const { return *m_body; }
+	bool isDoWhile() const { return m_isDoWhile; }
 
 private:
 	ASTPointer<Expression> m_condition;
 	ASTPointer<Statement> m_body;
+	bool m_isDoWhile;
 };
 
 /**

libsolidity/ast/ASTJsonConverter.cpp

@@ -264,7 +264,11 @@ bool ASTJsonConverter::visit(IfStatement const& _node)
 
 bool ASTJsonConverter::visit(WhileStatement const& _node)
 {
-	addJsonNode(_node, "WhileStatement", {}, true);
+	addJsonNode(
+		_node,
+		_node.isDoWhile() ? "DoWhileStatement" : "WhileStatement",
+		{},
+		true);
 	return true;
 }
 

libsolidity/ast/ASTPrinter.cpp

@@ -208,7 +208,7 @@ bool ASTPrinter::visit(IfStatement const& _node)
 
 bool ASTPrinter::visit(WhileStatement const& _node)
 {
-	writeLine("WhileStatement");
+	writeLine(_node.isDoWhile() ? "DoWhileStatement" : "WhileStatement");
 	printSourcePart(_node);
 	return goDeeper();
 }