fix interop and indexing oversights

compiler_tests.odin

@@ -2033,6 +2033,35 @@ sentinel_pointer_views_compile_and_run :: proc(t: ^testing.T) {
 	testing.expect_value(t, state.exit_code, 303)
 }
 
+@(test)
+milestone_24_regressions_compile_and_run :: proc(t: ^testing.T) {
+	output := "/tmp/brolang-test-milestone-24"
+	defer _ = os.remove(output)
+	status := compiler_core.compile_package("examples/programs/milestone_24", output)
+	testing.expect_value(t, status, 0)
+	state := run_executable(output)
+	testing.expect_value(t, state.exit_code, 0)
+}
+
+@(test)
+milestone_24_rejects_invalid_forms :: proc(t: ^testing.T) {
+	Case :: struct {
+		directory: string,
+		output:    string,
+	}
+	cases := [?]Case{
+		{"examples/programs/index_signed_error", "/tmp/brolang-test-index-signed-error"},
+		{"examples/programs/index_int_constraint_error", "/tmp/brolang-test-index-int-constraint-error"},
+		{"examples/programs/scalar_cast_error", "/tmp/brolang-test-scalar-cast-error"},
+		{"examples/programs/array_const_size_error", "/tmp/brolang-test-array-const-size-error"},
+	}
+	for test_case in cases {
+		status := compiler_core.compile_package(test_case.directory, test_case.output)
+		testing.expect_value(t, status, 1)
+		_ = os.remove(test_case.output)
+	}
+}
+
 @(test)
 control_flow_compiles_and_runs :: proc(t: ^testing.T) {
 	output := "/tmp/brolang-test-control-flow"