In the new variable model `this` is treate as a variable. Similarly to
other variables, it is placed into a variable context, which is
treated as the point of declaration of `this` variable. Since
parameter lists of a `FunctionNode`, such as
`FunctionNode.positionalParameters` and
`FunctionNode.namedParameters`, aren't treated as declarations either,
but rather as a convenient way to access the parameters, a similar
treatment of `this` variable is introduced in this CL, where it
becomes accessible via `FunctionNode.thisVariable`, in addition to
being declared in an appropriate variable context.
Part of https://github.com/dart-lang/sdk/issues/61572
Change-Id: Ia608fd01661353eb704de225f6b123900b1671b8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/494840
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Chloe Stefantsova <cstefantsova@google.com>
Chloe Stefantsova
c82c4632a1