Replace VariadicTuple and NonVariadicTuple with a single Tuple node.
The variadic property is now part of the tuple element and not of the whole tuple.
Simply mangling the derived method is no longer sufficient. Now also
mangle the base method, so that eventually we handle this sort of
scenario:
class Base {
// introduces: Base.method
func method(_: Int, _: Int) {}
}
class First : Base {
// overrides: Base.method
// introduces: First.method
override func method(_: Int?, _: Int) {}
}
class Second : First {
// overrides: Base.method, First.method
// introduces: Second.method
override func method(_: Int?, _: Int?) {}
}
Here, the override of Base.method by Second.method and the
override of First.method by Second.method require distinct
manglings even though the derived method (Second.method) is
the same in both cases.
Note that while the new mangling is longer, vtable thunks are
always emitted with private linkage, so with the exception of
the standard library which is built with -sil-serialize-all
they will not affect the size of dylibs.
The standard library itself has very few classes so it doesn't
matter there either.
This patch doesn't actually add any support to introduce new
vtable entries for methods that override; this is coming up
next.
Previously it was part of swiftBasic.
The demangler library does not depend on llvm (except some header-only utilities like StringRef). Putting it into its own library makes sure that no llvm stuff will be linked into clients which use the demangler library.
This change also contains other refactoring, like moving demangler code into different files. This makes it easier to remove the old demangler from the runtime library when we switch to the new symbol mangling.
Also in this commit: remove some unused API functions from the demangler Context.
fixes rdar://problem/30503344
