expose custom PVM settings in the standard json interface (#318)

Exposes the following PolkaVM specific options via the standard json
interface:
- Heap size
- Stack size
- Whether to emit source level debug information

Additionally it is now forbidden to specify those as CLI option in
standard JSON mode. They are bytecode altering options and having
multiple ways to specify them creates unnecessary room for confusion:
The standard JSON input description should be sufficient and succint for
reproducible builds.

Closes #290

---------

Signed-off-by: xermicus <bigcyrill@hotmail.com>

crates/solc-json-interface/src/standard_json/input/settings/polkavm/memory.rs

@@ -0,0 +1,21 @@
+//! The compile time PolkaVM memory configuration settings.
+
+use serde::{Deserialize, Serialize};
+
+/// The PolkaVM memory configuration.
+#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
+pub struct MemoryConfig {
+    /// The emulated EVM linear heap memory size in bytes.
+    pub heap_size: u32,
+    /// The PVM stack size in bytes.
+    pub stack_size: u32,
+}
+
+impl Default for MemoryConfig {
+    fn default() -> Self {
+        Self {
+            heap_size: 64 * 1024,
+            stack_size: 32 * 1024,
+        }
+    }
+}

crates/solc-json-interface/src/standard_json/input/settings/polkavm/mod.rs

@@ -0,0 +1,26 @@
+//! The `resolc --standard-json` polkavm settings.
+//!
+//! Used for options specific to PolkaVM which therefor don't exist in solc.
+
+use memory::MemoryConfig;
+use serde::{Deserialize, Serialize};
+
+pub mod memory;
+
+/// PVM specific compiler settings.
+#[derive(Clone, Copy, Default, Debug, Serialize, Deserialize)]
+pub struct PolkaVM {
+    /// The PolkaVM target machine memory configuration settings.
+    pub memory_config: MemoryConfig,
+    /// Instruct LLVM to emit debug information.
+    pub debug_information: bool,
+}
+
+impl PolkaVM {
+    pub fn new(memory_config: Option<MemoryConfig>, debug_information: bool) -> Self {
+        Self {
+            memory_config: memory_config.unwrap_or_default(),
+            debug_information,
+        }
+    }
+}