It correctly points out that despite `Type() = default;`, there's non-assigned const fields, so there's no way to generate a default constructor.

Bug: b/145351270
Change-Id: I1c680982d960df278b5fcca5b29e837a4c82b70d
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/43709
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Tested-by: Ben Clayton <bclayton@google.com>