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/sparc32/rshift.asm b/third_party/gmp/mpn/sparc32/rshift.asm
new file mode 100644
index 0000000..e155476
--- /dev/null
+++ b/third_party/gmp/mpn/sparc32/rshift.asm
@@ -0,0 +1,102 @@
+dnl  SPARC mpn_rshift -- Shift a number right.
+
+dnl  Copyright 1995, 1996, 2000 Free Software Foundation, Inc.
+
+dnl  This file is part of the GNU MP Library.
+dnl
+dnl  The GNU MP Library is free software; you can redistribute it and/or modify
+dnl  it under the terms of either:
+dnl
+dnl    * the GNU Lesser General Public License as published by the Free
+dnl      Software Foundation; either version 3 of the License, or (at your
+dnl      option) any later version.
+dnl
+dnl  or
+dnl
+dnl    * the GNU General Public License as published by the Free Software
+dnl      Foundation; either version 2 of the License, or (at your option) any
+dnl      later version.
+dnl
+dnl  or both in parallel, as here.
+dnl
+dnl  The GNU MP Library is distributed in the hope that it will be useful, but
+dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+dnl  for more details.
+dnl
+dnl  You should have received copies of the GNU General Public License and the
+dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
+dnl  see https://www.gnu.org/licenses/.
+
+
+include(`../config.m4')
+
+C INPUT PARAMETERS
+C res_ptr	%o0
+C src_ptr	%o1
+C size		%o2
+C cnt		%o3
+
+ASM_START()
+PROLOGUE(mpn_rshift)
+	ld	[%o1],%g2	C load first limb
+	sub	%g0,%o3,%o5	C negate shift count
+	add	%o2,-1,%o2
+	andcc	%o2,4-1,%g4	C number of limbs in first loop
+	sll	%g2,%o5,%g1	C compute function result
+	be	L(0)		C if multiple of 4 limbs, skip first loop
+	st	%g1,[%sp+80]
+
+	sub	%o2,%g4,%o2	C adjust count for main loop
+
+L(loop0):
+	ld	[%o1+4],%g3
+	add	%o0,4,%o0
+	add	%o1,4,%o1
+	addcc	%g4,-1,%g4
+	srl	%g2,%o3,%o4
+	sll	%g3,%o5,%g1
+	mov	%g3,%g2
+	or	%o4,%g1,%o4
+	bne	L(loop0)
+	 st	%o4,[%o0-4]
+
+L(0):	tst	%o2
+	be	L(end)
+	 nop
+
+L(loop):
+	ld	[%o1+4],%g3
+	add	%o0,16,%o0
+	addcc	%o2,-4,%o2
+	srl	%g2,%o3,%o4
+	sll	%g3,%o5,%g1
+
+	ld	[%o1+8],%g2
+	srl	%g3,%o3,%g4
+	or	%o4,%g1,%o4
+	st	%o4,[%o0-16]
+	sll	%g2,%o5,%g1
+
+	ld	[%o1+12],%g3
+	srl	%g2,%o3,%o4
+	or	%g4,%g1,%g4
+	st	%g4,[%o0-12]
+	sll	%g3,%o5,%g1
+
+	ld	[%o1+16],%g2
+	srl	%g3,%o3,%g4
+	or	%o4,%g1,%o4
+	st	%o4,[%o0-8]
+	sll	%g2,%o5,%g1
+
+	add	%o1,16,%o1
+	or	%g4,%g1,%g4
+	bne	L(loop)
+	 st	%g4,[%o0-4]
+
+L(end):	srl	%g2,%o3,%g2
+	st	%g2,[%o0-0]
+	retl
+	ld	[%sp+80],%o0
+EPILOGUE(mpn_rshift)