Employ test-bpf feature to make 'cargo test' pass

Cargo.toml

@@ -1,5 +1,6 @@
 [workspace]
 members = [
+  "associated-token-account/program",
   "memo/program",
   "shared-memory/program",
   "stake-pool/program",
@@ -14,6 +15,5 @@ members = [
   "utils/test-client",
 ]
 exclude = [
-  "associated-token-account/program", # Exclude until `cargo test` works
   "themis/client_ristretto",
 ]

associated-token-account/program/Cargo.toml

@@ -9,6 +9,7 @@ edition = "2018"
 
 [features]
 no-entrypoint = []
+test-bpf = []
 
 [dependencies]
 solana-program = "1.4.4"
@@ -24,5 +25,3 @@ crate-type = ["cdylib", "lib"]
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]
-
-[workspace]

associated-token-account/program/tests/functional.rs

@@ -1,3 +1,6 @@
+// Mark this test as BPF-only due to current `ProgramTest` limitations when CPIing into the system program
+#![cfg(feature = "test-bpf")]
+
 use solana_program::{instruction::*, program_pack::Pack, pubkey::Pubkey, system_instruction};
 use solana_program_test::*;
 use solana_sdk::{
@@ -10,8 +13,7 @@ fn program_test(token_mint_address: Pubkey) -> ProgramTest {
     let mut pc = ProgramTest::new(
         "spl_associated_token_account",
         id(),
-        // TODO: BPF only until native CPI rework in the monorepo completes
-        None, //processor!(processor::process_instruction),
+        processor!(processor::process_instruction),
     );
 
     // Add SPL Token program