internalize runtime API function symbols

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

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

@@ -0,0 +1,37 @@
+//! Runtime API import and export symbols.
+
+/// The contract deploy export.
+pub static CALL: &str = "call";
+
+/// The contract call export.
+pub static DEPLOY: &str = "deploy";
+
+/// All exported symbols.
+/// Useful for configuring common attributes and linkage.
+pub static EXPORTS: [&str; 2] = [CALL, DEPLOY];
+
+pub static GET_STORAGE: &str = "get_storage";
+
+pub static HASH_KECCAK_256: &str = "hash_keccak_256";
+
+pub static INPUT: &str = "input";
+
+pub static RETURN: &str = "seal_return";
+
+pub static SET_STORAGE: &str = "set_storage";
+
+pub static VALUE_TRANSFERRED: &str = "value_transferred";
+
+/// All imported runtime API symbols..
+/// Useful for configuring common attributes and linkage.
+pub static IMPORTS: [&str; 6] = [
+    GET_STORAGE,
+    HASH_KECCAK_256,
+    INPUT,
+    RETURN,
+    SET_STORAGE,
+    VALUE_TRANSFERRED,
+];
+
+/// PolkaVM __sbrk API symbol to extend the heap memory.
+pub static SBRK: &str = "__sbrk";