Reapply directory error handling change.

runtime/bin/platform_linux.cc

Index: runtime/bin/platform_linux.cc
diff --git a/runtime/bin/platform_linux.cc b/runtime/bin/platform_linux.cc
index 4771b665afe8b815dd62d865f22fa9770860ac4c..679f79cf3c242cab7bf5f98f5d05cc3762e564cb 100644
--- a/runtime/bin/platform_linux.cc
+++ b/runtime/bin/platform_linux.cc
@@ -4,6 +4,7 @@
 
 #include "bin/platform.h"
 
+#include <string.h>
 #include <unistd.h>
 
 
@@ -15,3 +16,16 @@ int Platform::NumberOfProcessors() {
 const char* Platform::OperatingSystem() {
   return "linux";
 }
+
+
+char* Platform::StrError(int error_code) {
+  static const int kBufferSize = 1024;
+  char* error = static_cast<char*>(malloc(kBufferSize));
+  error[0] = '\0';
+  char* error_str = strerror_r(error_code, error, kBufferSize);
+  if (error_str != error) {
+    size_t written = snprintf(error, kBufferSize, "%s", error_str);
+    ASSERT(written == strlen(error_str));
+  }
+  return error;
+}