Add support for implicit array size ESSL3 introduces implicit array size that is determined automatically according to the initializer. Implicit sizes are resolved when parsing constructors and when initializers are evaluated, so ANGLE's AST will not contain implicit sizes. Declarations where there are two differently sized arrays with the same implicitly sized type, for example: float[] a = float[](0.0), b = float[](0.0, 1.0); will be transformed into declarations where the two arrays don't share the array size like this: float a[1] = float[1](0.0), float b[2] = float[2](0.0, 1.0); so they are not a problem. Unlike sized arrays, implicitly sized arrays don't have a size limit enforced by the parser. Include a test that verifies that non-initialization of an implicitly sized array defined using ESSL3 type syntax is caught by the parser. Additionally tested with WebGL 2 test sdk/tests/deqp/data/gles3/shaders/arrays.html TEST=WebGL 2 conformance tests, angle_unittests BUG=angleproject:941 Change-Id: Ib55b7601848102a103af9db284a80f09abaeb021 Reviewed-on: https://chromium-review.googlesource.com/265653 Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Olli Etuaho <oetuaho@nvidia.com>