1b8f4ac1e7
Eliminate numerous type checks not needed in strong mode. Use private nullability annotations instead of inline JS to mark known non-null variables, and to make the compiler generate null checks for null checked variables. Use nullability annotations and code refactoring to remove redundant null checks and to move checks out of loops. BUG= R=jmesserly@google.com Review-Url: https://codereview.chromium.org/2994203002 .