Sever the last load-bearing link between SILFunction and SILConstant by naming SILFunctions with their mangled symbol names. Move the core of the mangler up to SIL, and teach SILGen how to use it to mangle a SILConstant.
Swift SVN r4964
Move AbstractCC into SILType and make it an attribute of SILTypes for functions. Add a ConvertCCInst to represent calling convention conversions. Give SILFunctions a linkage attribute. Add logic to SILGen to calculate these attributes for SILConstants based on their attached decls.
IRGen doesn't use these new attributes yet. I'll hook that up when I move mangling over.
Swift SVN r4886
Replace 'constant_ref' with 'function_ref', which references a SILFunction directly, and 'global_addr', which references a global variable VarDecl. Get rid of the SILConstant-to-SILFunction mapping in SILModule and replace it with an ilist of SILFunctions. Allow SILFunctions to be 'external' by not having any blocks in their body.
For now, SILFunctions still carry around their SILConstant "name", because name mangling and IRGen still rely on access to the original decl in order to recover IRGen information, which unfortunately leaves IRGen's CodeRefs in a gross, awkward intermediate state. Lifting mangling, AbstractCC, and other linkage attributes to SIL should clear up this up.
Swift SVN r4865
type, though; I had to define a WriteAsOperand function and
add a front() method to SILFunction to get this to work.
Rip out my dominators implementation and replace it with
LLVM's. I'd forgotten that LLVM's was actually generic.
Swift SVN r4717
