--- a/gcc/hash-table.c	Thu Oct 25 07:37:49 2018 +0900
+++ b/gcc/hash-table.c	Thu Feb 13 11:34:05 2020 +0900
@@ -1,5 +1,5 @@
 /* A type-safe hash table template.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2020 Free Software Foundation, Inc.
    Contributed by Lawrence Crowl <crowl@google.com>
 
 This file is part of GCC.
@@ -74,8 +74,11 @@
   { 0xfffffffb, 0x00000006, 0x00000008, 31 }
 };
 
+/* Limit number of comparisons when calling hash_table<>::verify.  */
+unsigned int hash_table_sanitize_eq_limit;
+
 /* The following function returns an index into the above table of the
-   nearest prime number which is greater than N, and near a power of two. */
+   nearest prime number which is at least N, and near a power of two. */
 
 unsigned int
 hash_table_higher_prime_index (unsigned long n)
@@ -121,3 +124,15 @@
       hash_table_usage ().dump (origin);
     }
 }
+
+/* Report a hash table checking error.  */
+
+ATTRIBUTE_NORETURN ATTRIBUTE_COLD
+void
+hashtab_chk_error ()
+{
+  fprintf (stderr, "hash table checking failed: "
+	   "equal operator returns true for a pair "
+	   "of values with a different hash value\n");
+  gcc_unreachable ();
+}