Add Kernel syntactic support for constants constructed by
bool.fromEnvironment, int.fromEnvironment, and String.fromEnvironment.
These values are not necessarily available at compile time. Because
constants can depend on these values, there is also an unevaluated constant
that represents an expression depending on environment values.
This syntax is not yet produced by the Fasta compiler.
Change-Id: Ie96ea7f60a7efcd35ac802b320a00f398d41232e
Reviewed-on: https://dart-review.googlesource.com/c/88827
Commit-Queue: Kevin Millikin <kmillikin@google.com>
Reviewed-by: Aske Simon Christensen <askesc@google.com>
Kevin Millikin
944984f015