Index: system.h
===================================================================
--- system.h    (revision 193045)
+++ system.h    (working copy)
@@ -774,6 +774,11 @@
 #undef strerror
  #pragma GCC poison strerror

+/* loc_t is defined on some systems and too inviting for some
+   programmers to avoid.  */
+#undef loc_t
+ #pragma GCC poison loc_t
+
 /* Old target macros that have moved to the target hooks structure.  */
  #pragma GCC poison ASM_OPEN_PAREN ASM_CLOSE_PAREN                     \
        FUNCTION_PROLOGUE FUNCTION_EPILOGUE                             \