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/tests/unit/standard_json.rs

@@ -0,0 +1,53 @@
+use std::path::PathBuf;
+
+use revive_solc_json_interface::SolcStandardJsonInput;
+
+use crate::test_utils::build_yul_standard_json;
+
+#[test]
+fn standard_json_yul_solc() {
+    let solc_input = SolcStandardJsonInput::try_from(Some(
+        PathBuf::from("src/tests/data/standard_json/yul_solc.json").as_path(),
+    ))
+    .unwrap();
+    let solc_output = build_yul_standard_json(solc_input).unwrap();
+
+    assert!(!solc_output
+        .contracts
+        .get("Test")
+        .expect("The `Test` contract is missing")
+        .get("Return")
+        .expect("The `Return` contract is missing")
+        .evm
+        .as_ref()
+        .expect("The `evm` field is missing")
+        .bytecode
+        .as_ref()
+        .expect("The `bytecode` field is missing")
+        .object
+        .is_empty())
+}
+
+#[test]
+fn standard_json_yul_solc_urls() {
+    let solc_input = SolcStandardJsonInput::try_from(Some(
+        PathBuf::from("src/tests/data/standard_json/yul_solc_urls.json").as_path(),
+    ))
+    .unwrap();
+    let solc_output = build_yul_standard_json(solc_input).unwrap();
+
+    assert!(!solc_output
+        .contracts
+        .get("Test")
+        .expect("The `Test` contract is missing")
+        .get("Return")
+        .expect("The `Return` contract is missing")
+        .evm
+        .as_ref()
+        .expect("The `evm` field is missing")
+        .bytecode
+        .as_ref()
+        .expect("The `bytecode` field is missing")
+        .object
+        .is_empty())
+}