support riscv64 target

Signed-off-by: xermicus <cyrill@parity.io>

crates/common/Cargo.toml

@@ -12,6 +12,9 @@ description = "Shared constants of the revive compiler"
 [lib]
 doctest = false
 
+[features]
+riscv-64 = []
+
 [dependencies]
 anyhow = { workspace = true }
 serde = { workspace = true, features = ["derive"] }

crates/common/src/byte_length.rs

@@ -7,7 +7,10 @@ pub const BYTE_LENGTH_BYTE: usize = 1;
 pub const BYTE_LENGTH_X32: usize = 4;
 
 /// Native stack alignment size in bytes
+#[cfg(not(feautre = "riscv-64"))]
 pub const BYTE_LENGTH_STACK_ALIGN: usize = 4;
+#[cfg(feautre = "riscv-64")]
+pub const BYTE_LENGTH_STACK_ALIGN: usize = 8;
 
 /// The x86_64 word byte-length.
 pub const BYTE_LENGTH_X64: usize = 8;