Fix failing map/set tests in IE11.
Fix failing map/set tests in IE11.

huyinghuan/lodash,huyinghuan/lodash,Xotic750/lodash,af7/lodash,AneesMohammed/lodash,steelsojka/lodash,chrootsu/lodash,stewx/lodash,hafeez-syed/lodash,javiosyc/lodash,benweet/lodash,jshanson7/lodash,mjosh954/lodash,andersonaguiar/lodash,beaugunderson/lodash,andersonaguiar/lodash,phillipalexander/lodash,Andrey-Pavlov/lodash,chrootsu/lodash,bnicart/lodash,woldie/lodash,neouser99/lodash,tquetano-r7/lodash,timruffles/lodash,imjerrybao/lodash,timruffles/lodash,mshoaibraja/lodash,IveWong/lodash,justintung/lodash,PhiLhoSoft/lodash,ror/lodash,hafeez-syed/lodash,lzheng571/lodash,justintung/lodash,Andrey-Pavlov/lodash,IveWong/lodash,andersonaguiar/lodash,phillipalexander/lodash,xiwc/lodash,mjosh954/lodash,af7/lodash,jshanson7/lodash,enng0227/lodash,hafeez-syed/lodash,ror/lodash,transGLUKator/lodash,rlugojr/lodash,reggi/lodash,AndBicScadMedia/lodash,tonyonodi/lodash,javiosyc/lodash,tejokumar/lodash,transGLUKator/lodash,stewx/lodash,AndBicScadMedia/lodash,beaugunderson/lodash,huyinghuan/lodash,neouser99/lodash,tejokumar/lodash,zestia/lodash,woldie/lodash,transGLUKator/lodash,zestia/lodash,tgriesser/lodash,steelsojka/lodash,bnicart/lodash,justintung/lodash,lekkas/lodash,tgriesser/lodash,Xotic750/lodash,woldie/lodash,reggi/lodash,PhiLhoSoft/lodash,IveWong/lodash,phillipalexander/lodash,boneskull/lodash,Droogans/lodash,Droogans/lodash,zestia/lodash,ror/lodash,lekkas/lodash,benweet/lodash,enng0227/lodash,javiosyc/lodash,xiwc/lodash,xiwc/lodash,Andrey-Pavlov/lodash,AndBicScadMedia/lodash,AneesMohammed/lodash,lzheng571/lodash,imjerrybao/lodash,mshoaibraja/lodash,boneskull/lodash,enng0227/lodash,tejokumar/lodash,tquetano-r7/lodash,jshanson7/lodash,benweet/lodash,AneesMohammed/lodash,Droogans/lodash,imjerrybao/lodash,chrootsu/lodash,stewx/lodash,timruffles/lodash,mshoaibraja/lodash,mjosh954/lodash,lekkas/lodash,prawnsalad/lodash,tonyonodi/lodash,PhiLhoSoft/lodash,bnicart/lodash,tgriesser/lodash,tquetano-r7/lodash,neouser99/lodash,prawnsalad/lodash,reggi/lodash,Xotic750/lodash,lzheng571/lodash,msmorgan/lodash,af7/lodash,rlugojr/lodash,prawnsalad/lodash,msmorgan/lodash