[TIMOB-11093] iOS: Update jscore to 538.11.1 version from https://github.com/phoboslab/JavaScriptCore-iOS.
Merge pull request #6447 from matt-langston/TIMOB-11093_3_5_X_v2-phoboslab

[TIMOB-11093] iOS: Update jscore to 538.11.1 version