Add libgmp 6.2.0 to third_party

Don't build it yet.  That will come in the next review.

Change-Id: Idf3266558165e5ab45f4a41c98cc8c838c8244d5
diff --git a/third_party/gmp/mpn/mips32/gmp-mparam.h b/third_party/gmp/mpn/mips32/gmp-mparam.h
new file mode 100644
index 0000000..986135d
--- /dev/null
+++ b/third_party/gmp/mpn/mips32/gmp-mparam.h
@@ -0,0 +1,72 @@
+/* gmp-mparam.h -- Compiler/machine parameter header file.
+
+Copyright 1991, 1993, 1994, 1999-2002 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of either:
+
+  * the GNU Lesser General Public License as published by the Free
+    Software Foundation; either version 3 of the License, or (at your
+    option) any later version.
+
+or
+
+  * the GNU General Public License as published by the Free Software
+    Foundation; either version 2 of the License, or (at your option) any
+    later version.
+
+or both in parallel, as here.
+
+The GNU MP Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received copies of the GNU General Public License and the
+GNU Lesser General Public License along with the GNU MP Library.  If not,
+see https://www.gnu.org/licenses/.  */
+
+
+#define GMP_LIMB_BITS 32
+#define GMP_LIMB_BYTES 4
+
+
+/* Generated by tuneup.c, 2002-02-20, gcc 2.95 (R3000) */
+
+#define MUL_TOOM22_THRESHOLD             20
+#define MUL_TOOM33_THRESHOLD             50
+
+#define SQR_BASECASE_THRESHOLD            7
+#define SQR_TOOM2_THRESHOLD              57
+#define SQR_TOOM3_THRESHOLD              78
+
+#define DIV_SB_PREINV_THRESHOLD           0  /* always */
+#define DIV_DC_THRESHOLD                 57
+#define POWM_THRESHOLD                   78
+
+#define GCD_ACCEL_THRESHOLD               3
+#define JACOBI_BASE_METHOD                2
+
+#define DIVREM_1_NORM_THRESHOLD           0  /* always */
+#define DIVREM_1_UNNORM_THRESHOLD         0  /* always */
+#define MOD_1_NORM_THRESHOLD              0  /* always */
+#define MOD_1_UNNORM_THRESHOLD            0  /* always */
+#define USE_PREINV_DIVREM_1               1
+#define USE_PREINV_MOD_1                  1
+#define DIVREM_2_THRESHOLD                0  /* always */
+#define DIVEXACT_1_THRESHOLD              0  /* always */
+#define MODEXACT_1_ODD_THRESHOLD          0  /* always */
+
+#define GET_STR_DC_THRESHOLD             19
+#define GET_STR_PRECOMPUTE_THRESHOLD     25
+#define SET_STR_THRESHOLD               309
+
+#define MUL_FFT_TABLE  { 496, 1056, 2176, 5632, 14336, 40960, 0 }
+#define MUL_FFT_MODF_THRESHOLD          624
+#define MUL_FFT_THRESHOLD              5888
+
+#define SQR_FFT_TABLE  { 496, 1184, 2176, 5632, 14336, 40960, 0 }
+#define SQR_FFT_MODF_THRESHOLD          560
+#define SQR_FFT_THRESHOLD              5376