Only check for simple parameter lists when the function explicitly enables strict
Only check for simple parameter lists when the function explicitly enables strict

Issue #496

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