Fix implementation for balance_of (#79)

The balance_of syscall is now available in pallet-revive.
- Fix balance_of implementation to use correct runtime api
- Add build_address_argument_store helper to be used for address arguments

crates/llvm-context/src/polkavm/const/runtime_api.rs

@@ -17,6 +17,8 @@ pub mod imports {
 
     pub static BALANCE: &str = "balance";
 
+    pub static BALANCE_OF: &str = "balance_of";
+
     pub static BLOCK_NUMBER: &str = "block_number";
 
     pub static CHAIN_ID: &str = "chain_id";
@@ -55,9 +57,10 @@ pub mod imports {
 
     /// All imported runtime API symbols.
     /// Useful for configuring common attributes and linkage.
-    pub static IMPORTS: [&str; 20] = [
+    pub static IMPORTS: [&str; 21] = [
         ADDRESS,
         BALANCE,
+        BALANCE_OF,
         BLOCK_NUMBER,
         CALL,
         CALLER,