bazel: Drop dependency on util/flags.h in runfiles helper

Bazel's `Runfiles::Create()` does not actually need a value for `argv0` in
order to find runfiles for the current `cc_binary`.

- Rename `runfiles.cc` to `runfiles_nobazel.cc`

PiperOrigin-RevId: 443061178
Change-Id: I31e16d69d24aecbc403f9407fc08c615bb1e8f9f

sandboxed_api/testing.cc

@@ -22,7 +22,7 @@ namespace sapi {
 std::string GetTestTempPath(absl::string_view name) {
   // When using Bazel, the environment variable TEST_TMPDIR is guaranteed to be
   // set.
-  // See https://docs.bazel.build/versions/master/test-encyclopedia.html for
+  // See https://bazel.build/reference/test-encyclopedia#initial-conditions for
   // details.
   const char* test_tmpdir = getenv("TEST_TMPDIR");
   return file::JoinPath(test_tmpdir ? test_tmpdir : ".", name);

sandboxed_api/util/BUILD.bazel

@@ -125,7 +125,7 @@ cc_library(
 
 cc_library(
     name = "runfiles",
-    srcs = ["runfiles.cc"],
+    srcs = ["runfiles_bazel.cc"],
     hdrs = ["runfiles.h"],
     copts = sapi_platform_copts(),
     visibility = ["//visibility:public"],

sandboxed_api/util/runfiles_bazel.cc

@@ -15,7 +15,6 @@
 #include <cstdlib>
 
 #include "absl/strings/str_format.h"
-#include "sandboxed_api/util/flag.h"
 #include "sandboxed_api/util/path.h"
 #include "sandboxed_api/util/raw_logging.h"
 #include "sandboxed_api/util/runfiles.h"
@@ -28,7 +27,7 @@ std::string GetDataDependencyFilePath(absl::string_view relative_path) {
 
   static Runfiles* runfiles = []() {
     std::string error;
-    auto* runfiles = Runfiles::Create(gflags::GetArgv0(), &error);
+    auto* runfiles = Runfiles::Create(/*argv=*/"" /* unknown */, &error);
     SAPI_RAW_CHECK(runfiles != nullptr, error.c_str());
 
     // Setup environment for child processes.