LinearMap is quite a bit faster, and is fully owned/sendable without
requiring copies. The older std::map also doesn't use explicit self and
relies on mutable fields.
- Make `extern fn()` assignable to any closure type, rather than
a subtype.
- Remove unused int_ty_set and float_ty_set
- Refactor variable unification and make it more DRY
- Do fn sub/lub/glb on the level of fn_sig
- Rename infer::to_str::ToStr to infer::to_str::InferStr
- Capitalize names of various types
- Correct hashing of FnMeta
- Convert various records-of-fns into structs-of-fns. This is both
eliminating use of deprecated features and more forwards compatible
with fn reform.
r=pcwalton
and rename "class" to "struct" everywhere possible (except local
vars, I was too lazy for that) -- that is why this commit is so
big.
No review, just dead code removal and renaming.
Closes#3515
