Protection of global variable names is case insensitive

Write a single line program, `var ELLIPSE = 1;` and note that Yoko Oh Noes gets bent out of shape re. redefining "ellipse". Remove the "var" and note that Yoko Oh Noes has no idea re. that identifier.

No source file, test, or entry point is named. Start by running the reported `var ELLIPSE = 1;` example in the live editor, then compare it with the version without `var` and trace the global-name protection behavior. Done means the reported case-insensitive handling is corrected and both examples behave as intended.

Written by the indexing model from the issue text.