upb: s/std::endl/'\n' in upb_generator

PiperOrigin-RevId: 572511446
diff --git a/upb_generator/BUILD b/upb_generator/BUILD
index c960273..bf0a1b9 100644
--- a/upb_generator/BUILD
+++ b/upb_generator/BUILD
@@ -362,6 +362,8 @@
     deps = [
         ":plugin_upb_proto",
         ":upbdev",
+        "//upb:base",
+        "//upb:mem",
         "//upb:port",
         "@com_google_absl//absl/log:absl_log",
         "@com_google_absl//absl/strings",
diff --git a/upb_generator/protoc-gen-upbdev.cc b/upb_generator/protoc-gen-upbdev.cc
index d2461dd..ce3bc69 100644
--- a/upb_generator/protoc-gen-upbdev.cc
+++ b/upb_generator/protoc-gen-upbdev.cc
@@ -32,6 +32,9 @@
 #include <string>
 
 #include "google/protobuf/compiler/plugin.upb.h"
+#include "upb/base/status.h"
+#include "upb/base/string_view.h"
+#include "upb/mem/arena.h"
 #include "upb_generator/subprocess.h"
 #include "upb_generator/upbdev.h"
 
@@ -61,7 +64,7 @@
   const upb_StringView sv =
       upbdev_ProcessInput(input.data(), input.size(), a, &status);
   if (!upb_Status_IsOk(&status)) {
-    std::cerr << status.msg << std::endl;
+    std::cerr << status.msg << '\n';
     return -1;
   }
 
@@ -75,14 +78,14 @@
   const bool ok = subprocess.Communicate(json_request, &json_response, &error);
   if (!ok) {
     // Dump the JSON request to stderr if we can't launch the next plugin.
-    std::cerr << json_request << std::endl;
+    std::cerr << json_request << '\n';
     return -1;
   }
 
   // Decode, serialize, and write the JSON response.
   upbdev_ProcessOutput(json_response.data(), json_response.size(), a, &status);
   if (!upb_Status_IsOk(&status)) {
-    std::cerr << status.msg << std::endl;
+    std::cerr << status.msg << '\n';
     return -1;
   }
 
diff --git a/upb_generator/subprocess.cc b/upb_generator/subprocess.cc
index 0f6f8b4..5280dc0 100644
--- a/upb_generator/subprocess.cc
+++ b/upb_generator/subprocess.cc
@@ -357,7 +357,7 @@
 bool Subprocess::Communicate(const std::string& input_data,
                              std::string* output_data, std::string* error) {
   if (child_stdin_ == -1) {
-    std::cerr << "Must call Start() first." << std::endl;
+    std::cerr << "Must call Start() first." << '\n';
     UPB_ASSERT(child_stdin_ != -1);
   }
 
@@ -387,7 +387,7 @@
         // Interrupted by signal.  Try again.
         continue;
       } else {
-        std::cerr << "select: " << strerror(errno) << std::endl;
+        std::cerr << "select: " << strerror(errno) << '\n';
         UPB_ASSERT(0);
       }
     }
@@ -434,7 +434,7 @@
   int status;
   while (waitpid(child_pid_, &status, 0) == -1) {
     if (errno != EINTR) {
-      std::cerr << "waitpid: " << strerror(errno) << std::endl;
+      std::cerr << "waitpid: " << strerror(errno) << '\n';
       UPB_ASSERT(0);
     }
   }