upgrade GMP to version 6.2.0

[dimpase]

Release notes:

• https://gmplib.org/gmp6.2

Our current version is gmp 6.1.2, outdated.

Previous upgrade:

• Upgrade GMP #19706 (Upgrade GMP) - merged in Sage 8.1.beta7, released 2017-10

see upstream_url for the tarball

CC: @dimpase @kiwifb @koffie @slel @jhpalmieri

Component: packages: standard

Keywords: upgrade, gmp

Author: Dima Pasechnik

Branch/Commit: f331395

Reviewer: Isuru Fernando

Issue created by migration from https://trac.sagemath.org/ticket/30625

[slel]

Changed keywords from none to upgrade, gmp

[slel]

Description changed:

--- 
+++ 
@@ -1 +1,10 @@
-our current version is 6.1.2, outdated.
+Release notes:
+
+- https://gmplib.org/gmp6.2
+
+Our current version is gmp 6.1.2, outdated.
+
+Previous upgrade:
+
+- #19706 (Upgrade GMP) - merged in Sage 8.1.beta7, released 2017-10
+

[slel]

comment:1

Available upstream tarballs:

• lz, 2005993 bytes, https://gmplib.org/download/gmp/gmp-6.2.0.tar.lz
• xz, 2012444 bytes, https://gmplib.org/download/gmp/gmp-6.2.0.tar.xz
• zstd, 2103070 bytes, https://gmplib.org/download/gmp/gmp-6.2.0.tar.zst

Do we go for the smallest one, or do we have a preference for .xz?

For gmp 6.1.2 we used .bz2 but I don't see that listed at

• https://gmplib.org/#DOWNLOAD

[dimpase]

comment:2

xz is well-tested, the difference is 0.5% wrt to lz, let's stick with xz

-- even though "xz" an abbreviated Russian for NFC

[dimpase]

Author: Dima Pasechnik

[dimpase]

Commit: 9e6f4b1

[dimpase]

Description changed:

--- 
+++ 
@@ -8,3 +8,5 @@
 
 - #19706 (Upgrade GMP) - merged in Sage 8.1.beta7, released 2017-10
 
+see upstream_url for the tarball
+

[dimpase]

Branch: u/dimpase/packages/gmp620

[dimpase]

New commits:

9e6f4b1

update gmp tp version 6.2.0