Separate compilation and linker phases (#376)

Separate between compilation and linker phases to allow deploy time
linking and back-porting era compiler changes to fix #91. Unlinked
contract binaries (caused by missing libraries or missing factory
dependencies in turn) are emitted as raw ELF object.

Few drive by fixes:
- #98
- A compiler panic on missing libraries definitions.
- Fixes some incosistent type forwarding in JSON output (empty string
vs. null object).
- Remove the unused fallback for size optimization setting.
- Remove the broken `--lvm-ir`  mode.
- CI workflow fixes.

---------

Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>
Signed-off-by: xermicus <bigcyrill@hotmail.com>
Signed-off-by: xermicus <cyrill@parity.io>

crates/resolc/src/project/contract/ir/mod.rs

@@ -1,66 +1,40 @@
 //! The contract source code.
 
-pub mod llvm_ir;
-pub mod yul;
-
-use std::collections::HashSet;
+use std::collections::BTreeSet;
 
 use serde::Deserialize;
 use serde::Serialize;
 
-use revive_yul::parser::statement::object::Object;
-
-use self::llvm_ir::LLVMIR;
 use self::yul::Yul;
 
+pub mod yul;
+
 /// The contract source code.
 #[derive(Debug, Serialize, Deserialize, Clone)]
 #[allow(clippy::upper_case_acronyms)]
 pub enum IR {
     /// The Yul source code.
     Yul(Yul),
-    /// The LLVM IR source code.
-    LLVMIR(LLVMIR),
 }
 
 impl IR {
-    /// A shortcut constructor.
-    pub fn new_yul(source_code: String, object: Object) -> Self {
-        Self::Yul(Yul::new(source_code, object))
-    }
-
-    /// A shortcut constructor.
-    pub fn new_llvm_ir(path: String, source: String) -> Self {
-        Self::LLVMIR(LLVMIR::new(path, source))
+    /// Drains the list of factory dependencies.
+    pub fn drain_factory_dependencies(&mut self) -> BTreeSet<String> {
+        match self {
+            IR::Yul(ref mut yul) => yul.object.factory_dependencies.drain().collect(),
+        }
     }
 
     /// Get the list of missing deployable libraries.
-    pub fn get_missing_libraries(&self) -> HashSet<String> {
+    pub fn get_missing_libraries(&self) -> BTreeSet<String> {
         match self {
             Self::Yul(inner) => inner.get_missing_libraries(),
-            Self::LLVMIR(_inner) => HashSet::new(),
         }
     }
 }
 
-impl<D> revive_llvm_context::PolkaVMWriteLLVM<D> for IR
-where
-    D: revive_llvm_context::PolkaVMDependency + Clone,
-{
-    fn declare(
-        &mut self,
-        context: &mut revive_llvm_context::PolkaVMContext<D>,
-    ) -> anyhow::Result<()> {
-        match self {
-            Self::Yul(inner) => inner.declare(context),
-            Self::LLVMIR(_inner) => Ok(()),
-        }
-    }
-
-    fn into_llvm(self, context: &mut revive_llvm_context::PolkaVMContext<D>) -> anyhow::Result<()> {
-        match self {
-            Self::Yul(inner) => inner.into_llvm(context),
-            Self::LLVMIR(_inner) => Ok(()),
-        }
+impl From<Yul> for IR {
+    fn from(inner: Yul) -> Self {
+        Self::Yul(inner)
     }
 }