Translator: Fix HLSL vs for loop's init not having initializer The handleExcessiveLoop code expected that if a for loop has an init expression that it must necessarily have an initializer as well. That is not true in (fuzzer-produced) code such as following: for (int i; ...; ...) Bug: chromium:1238182 Change-Id: Id761e937a34a6b2feac1266e22207350a3bd616c Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3170114 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com>