feat(bindings)!: add RVM/Program support across FFI and language bindings (#565)

- FFI: add RVM/Program APIs, execution state accessors, HostAwait handling, and buffer/result helpers in rvm.rs, common.rs, engine.rs.
- Compiler: emit HostAwait for __builtin_host_await in function_calls.rs.
- RVM tests: add HostAwait regression cases and extend harness for suspend/resume responses in host_await.yaml and mod.rs.
- C/C++: add RVM tests/examples and wrapper updates in rvm_tests.c, rvm_tests.cpp, regorus.hpp, plus CMake wiring.
- C#: add Program/Rvm bindings, SafeHandle/PInvoke, tests, and example usage in Regorus, RvmProgramTests.cs, Program.cs, and README updates.
- Go: add Program/Rvm bindings, tests, and examples in rvm.go, rvm_test.go, main.go.
- Java: add Program/Rvm bindings, JNI glue, and examples in lib.rs, regorus, Test.java.
- Python: add Program/Rvm bindings and examples in lib.rs, test.py.
- WASM: add Program/Rvm bindings and examples in lib.rs, test.js.
- Tooling: wire binding tests in xtask and ignore generated Java artifacts in .gitignore.

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

bindings/go/main.go

@@ -100,4 +100,138 @@ func main() {
 		os.Exit(1)
 	}
 	fmt.Printf("%s\n", output)
+
+	// RVM regular example (compile, serialize, execute)
+	const regularPolicy = `
+package demo
+import rego.v1
+
+default allow := false
+
+allow if {
+  input.user == "alice"
+  input.active == true
+}
+`
+	const regularInput = `{"user":"alice","active":true}`
+
+	regularModules := []regorus.PolicyModule{{Id: "demo.rego", Content: regularPolicy}}
+	regularEntryPoints := []string{"data.demo.allow"}
+	regularProgram, err := regorus.CompileProgramFromModules("{}", regularModules, regularEntryPoints)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	defer regularProgram.Close()
+
+	listing, err := regularProgram.GenerateListing()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	fmt.Printf("RVM listing:\n%s\n", listing)
+
+	binary, err := regularProgram.SerializeBinary()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	regularProgram.Close()
+
+	rehydrated, isPartial, err := regorus.DeserializeProgram(binary)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	if isPartial {
+		fmt.Fprintf(os.Stderr, "error: program marked partial\n")
+		os.Exit(1)
+	}
+	defer rehydrated.Close()
+
+	regularVm, err := regorus.NewRvm()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	defer regularVm.Close()
+
+	if err := regularVm.LoadProgram(rehydrated); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	if err := regularVm.SetInputJson(regularInput); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+
+	regularResult, err := regularVm.Execute()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	fmt.Printf("RVM regular result: %s\n", regularResult)
+
+	// RVM HostAwait example
+	const rvmPolicy = `
+package demo
+import rego.v1
+
+default allow := false
+
+allow if {
+  input.account.active == true
+  details := __builtin_host_await(input.account.id, "account")
+  details.tier == "gold"
+}
+`
+	const rvmInput = `{"account":{"id":"acct-1","active":true}}`
+
+	modules := []regorus.PolicyModule{{Id: "demo.rego", Content: rvmPolicy}}
+	entryPoints := []string{"data.demo.allow"}
+	program, err := regorus.CompileProgramFromModules("{}", modules, entryPoints)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	defer program.Close()
+
+	vm, err := regorus.NewRvm()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	defer vm.Close()
+
+	if err := vm.SetExecutionMode(1); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	if err := vm.LoadProgram(program); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	if err := vm.SetInputJson(rvmInput); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+
+	if _, err := vm.Execute(); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+
+	state, err := vm.GetExecutionState()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	fmt.Printf("HostAwait state: %s\n", state)
+
+	result, err := vm.Resume(`{"tier":"gold"}`, true)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+	fmt.Printf("HostAwait result: %s\n", result)
 }