Misc. improvements

• Emit non-zero array constants properly
• Emit only actually used array constants per runtime wrapper
• Juno CLI
• Use repr(C) structs for product types
• Minimal implementation of SROA
• TODO: inlining, codegen cast, intrinsics, dynamic constant math

hercules_cg/src/cpu.rs

@@ -226,6 +226,9 @@ impl<'a> PartitionContext<'a> {
         // pointers to some memory at the LLVM IR level. This memory is passed
         // in as a parameter for anything involving arrays, and is alloca-ed for
         // product and summation types.
+        // TODO: actually do this ^ for products. Right now, products are still
+        // done at the LLVM struct level w/ GEP and so on. Apologies for anyone
+        // else reading this comment.
         let mut generate_index_code = |collect: NodeID, indices: &[Index]| -> std::fmt::Result {
             // Step 1: calculate the list of collection types corresponding to
             // each index.