ESSL -> WGSL: Emit most types and function params This emits struct declarations, as well as array/matrix/vec types. As a result this also emits function parameters. Bug: angleproject:42267100 Change-Id: Ib9c7e543fd38f7c1dfa64d8e63b054fc5111b336 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5598298 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Matthew Denton <mpdenton@chromium.org>