Disable automatic const insertion in analyzer

[dgrove]

disable automatic const insertion in analyzer - CL is done, scheglov needs to un-revert it.

(This is part of the work for finishing optional new/const)

[bwilkerson]

I think there's been some confusion between two separate pieces of work. I have a CL to make the optional new and const support in analyzer match the latest spec. Konstantin has a CL to make server stop adding const in places where it isn't necessary (which will need to be updated to match the latest spec). Sorry if I caused the confusion.

[bwilkerson]

https://dart-review.googlesource.com/c/sdk/+/50120

[Hixie]

I don't quite understand this bug... the analyzer will still tell people to add const where they've omitted new but where const would be possible, right?

[bwilkerson]

We can (if we don't already) have a lint for that, but this issue isn't about what advice the analyzer gives, but rather how it understands what the user has actually written. The analyzer originally implemented an earlier version of the optional new and const proposal; this issue was about making it consistent with the newer version that the CFE had implemented.