Merge branch 'fix-to-loopy-expr-for-subscripted-vars' of...

Merge branch 'fix-to-loopy-expr-for-subscripted-vars' of https://gitlab.tiker.net/inducer/grudge into dagrt-fusion

* 'fix-to-loopy-expr-for-subscripted-vars' of https://gitlab.tiker.net/inducer/grudge:
  ToLoopyExpressionMapper.map_variable_ref_expr: reuse name if already in lookup table
  Fix ToLoopyExpressionMapper for subscripted variables