This fixes a crash when referencing partially-applied methods
from @_inlineable functions.
Also, curry thunks for private methods do not need shared
linkage; private is sufficient.
Also, add a third [serializable] state for functions whose bodies we
*can* serialize, but only do so if they're referenced from another
serialized function.
This will be used for bodies synthesized for imported definitions,
such as init(rawValue:), etc, and various thunks, but for now this
change is NFC.
A transparent function might be deserialized and inlined into a function
in another module, which would cause problems if the function referenced
local functions.
Previously we would force local functions to have public linkage instead,
which worked, but was not resilient if the body of the transparent
function changed in the module that contained it.
Add a library evolution test ensuring that such a change is resilient
now.
Part of https://bugs.swift.org/browse/SR-267.
And include some supplementary mangling changes:
- Give the first generic param (depth=0, index=0) a single character mangling. Even after removing the self type from method declaration types, 'Self' still shows up very frequently in protocol requirement signatures.
- Fix the mangling of generic parameter counts to elide the count when there's only one parameter at the starting depth of the mangling.
Together these carve another 154KB out of a debug standard library. There's some awkwardness in demangled strings that I'll clean up in subsequent commits; since decl types now only mangle the number of generic params at their own depth, it's context-dependent what depths those represent, which we get wrong now. Currying markers are also wrong, but since free function currying is going away, we can mangle the partial application thunks in different ways.
Swift SVN r32896
'Ss' appears in manglings tens of thousands of times in the standard library and is also incredibly frequent in other modules. This alone is enough to shrink the standard library by 59KB.
Swift SVN r32409
