Translator: Don't validate structs on non-root nodes Struct validation needs to know about structs that may have been defined outside the scope of the node, so this validation (similar to variable and function call validation) is disabled when validation a subtree of the AST. Bug: angleproject:7531 Bug: b/239207278 Change-Id: Id6dcee041a40f09f0c36a9ef3bfc238433b69c58 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3812047 Auto-Submit: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Yuxin Hu <yuxinhu@google.com> Reviewed-by: Yuxin Hu <yuxinhu@google.com>