The compiler's parsing code has logic to recover from incomplete open
tags (i.e. `<div`) but the recovery logic does not handle when the
incomplete tag is terminated by an EOF. This commit updates the logic to
allow for the EOF character to be interpreted as the end of the tag open
so that the parser can continue processing. It will then fail to find
the end tag and recover by marking the open tag as incomplete.
Part of https://github.com/angular/vscode-ng-language-service/issues/1140
PR Close#41054
736b1f9fd4