The MoveDeclarationOutOfIf quick fix modified a IfStatementAST in case
there were several such ASTs in interface->path(). The resulting AST was
invalid (else_statement was pointing to 'this' afterwards), thus the
afterwards executed PointerDeclarationFormatter (an ASTVisitor) was not
able to finish his visit.

The actual problem was that op->pattern in the match() calls was not
reset.

Task-number: QTCREATORBUG-10919
Change-Id: Ifbcac73e75690321ef45b6d8c2dc32fcea236efa
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>