Make reserved words in import specifiers a recoverable error.
Make reserved words in import specifiers a recoverable error.

We already do this for reserved words in other places.

mathiasbynens/acorn,mathiasbynens/acorn,TimothyGu/acorn,ajaxorg/acorn,marijnh/acorn,marijnh/acorn,marijnh/acorn,TimothyGu/acorn,mathiasbynens/acorn,MarcelGerber/acorn,MarcelGerber/acorn,mysticatea/acorn,ternjs/acorn,ajaxorg/acorn,ternjs/acorn,TimothyGu/acorn,mysticatea/acorn,ternjs/acorn,ajaxorg/acorn,mysticatea/acorn,MarcelGerber/acorn