sandbox: move Codegen into bpf_dsl directory

sandbox/linux/BUILD.gn

Index: sandbox/linux/BUILD.gn
diff --git a/sandbox/linux/BUILD.gn b/sandbox/linux/BUILD.gn
index 96df5fd69b286adaa3d944a294828f42208c65ac..d4f3fe2d01d85a4098701e30eae29389f3f9e717 100644
--- a/sandbox/linux/BUILD.gn
+++ b/sandbox/linux/BUILD.gn
@@ -100,11 +100,11 @@ test("sandbox_linux_unittests") {
     sources += [
       "bpf_dsl/bpf_dsl_more_unittest.cc",
       "bpf_dsl/bpf_dsl_unittest.cc",
+      "bpf_dsl/codegen_unittest.cc",
       "bpf_dsl/cons_unittest.cc",
       "seccomp-bpf-helpers/baseline_policy_unittest.cc",
       "seccomp-bpf-helpers/syscall_parameters_restrictions_unittests.cc",
       "seccomp-bpf/bpf_tests_unittest.cc",
-      "seccomp-bpf/codegen_unittest.cc",
       "seccomp-bpf/errorcode_unittest.cc",
       "seccomp-bpf/sandbox_bpf_unittest.cc",
       "seccomp-bpf/syscall_iterator_unittest.cc",
@@ -146,6 +146,8 @@ component("seccomp_bpf") {
     "bpf_dsl/bpf_dsl.h",
     "bpf_dsl/bpf_dsl_forward.h",
     "bpf_dsl/bpf_dsl_impl.h",
+    "bpf_dsl/codegen.cc",
+    "bpf_dsl/codegen.h",
     "bpf_dsl/cons.h",
     "bpf_dsl/dump_bpf.cc",
     "bpf_dsl/dump_bpf.h",
@@ -154,8 +156,6 @@ component("seccomp_bpf") {
     "bpf_dsl/policy_compiler.cc",
     "bpf_dsl/policy_compiler.h",
     "bpf_dsl/trap_registry.h",
-    "seccomp-bpf/codegen.cc",
-    "seccomp-bpf/codegen.h",
     "seccomp-bpf/die.cc",
     "seccomp-bpf/die.h",
     "seccomp-bpf/errorcode.cc",