StaticPointers: Allow closed vars in the static form.
Summary: With this patch closed variables are allowed regardless of whether they are bound at the top level or not. The FloatOut pass is always performed. When optimizations are disabled, only expressions that go to the top level are floated. Thus, the applications of the StaticPtr data constructor are always floated. The CoreTidy pass makes sure the floated applications appear in the symbol table of object files. It also collects the floated bindings and inserts them in the static pointer table. The renamer does not check anymore if free variables appearing in the static form are top-level. Instead, the typechecker looks at the tct_closed flag to decide if the free variables are closed. The linter checks that applications of StaticPtr only occur at the top of top-level bindings after the FloatOut pass. The field spInfoName of StaticPtrInfo has been removed. It used to contain the name of the top-level binding that contains the StaticPtr application. However, this information is no longer available when the StaticPtr is constructed, as the binding name is determined now by the FloatOut pass. Test Plan: ./validate Reviewers: goldfire, simonpj, austin, hvr, bgamari Reviewed By: simonpj Subscribers: thomie, mpickering, mboes Differential Revision: https://phabricator.haskell.org/D2104 GHC Trac Issues: #11656