Just make Literal an expression. The ScalarConstructorExpression
provides no real value, aside from having a ConstructorExpression base
class that's common between ScalarConstructorExpression and
TypeConstructorExpression. TypeConstructorExpression will be folded into
CallExpression, so this hierarchy will serve no purpose.
First step in resolving the parser ambiguity of type-constructors vs
type-casts vs function calls.
Bug: tint:888
Change-Id: I2585d5ddbf6c0619a8f24c503e61ebf27c182ebe
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/68524
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: James Price <jrprice@google.com>