patch: bump to 2.7.6, switch to tar.xz, add gcc2 patch. (#3200)

The 2nd patch in patch-2.7.6-gcc2.patchset is almost identical to
the 2nd one in tar-1.30-gcc2.patchset, and the files they patch:

*    tar-1.30/gnu/backupfile.c *    tar-1.30/gnu/parse-datetime.y
* patch-2.7.6/lib/backupfile.c * patch-2.7.6/lib/parse-datetime.y

are identical before and after the patch. There is only one diff,
in line 3: we have a "2017" for tar and a "2018" for patch.

sys-devel/patch/patch-2.7.6.recipe

@@ -1,15 +1,20 @@
 SUMMARY="Utility to apply diffs to files"
-DESCRIPTION="
-Patch takes a patch file containing a difference listing produced by the diff \
-program and applies those differences to one or more original files, producing \
-patched versions."
-HOMEPAGE="http://www.gnu.org/software/patch/"
-COPYRIGHT="2012-2015 Free Software Foundation, Inc."
+DESCRIPTION="Patch takes a patch file containing a difference listing produced \
+by the diff program and applies those differences to one or more original \
+files, producing patched versions."
+HOMEPAGE="https://savannah.gnu.org/projects/patch/"
+COPYRIGHT="2012-2018 Free Software Foundation, Inc."
 LICENSE="GNU GPL v3"
-REVISION="2"
-SOURCE_URI="http://ftp.gnu.org/pub/gnu/patch/patch-$portVersion.tar.gz"
-CHECKSUM_SHA256="7436f5a19f93c3ca83153ce9c5cbe4847e97c5d956e57a220121e741f6e7968f"
+REVISION="1"
+SOURCE_URI="https://ftpmirror.gnu.org/patch/patch-$portVersion.tar.xz
+	https://ftp.gnu.org/gnu/patch/patch-$portVersion.tar.xz"
+CHECKSUM_SHA256="ac610bda97abe0d9f6b7c963255a11dcb196c25e337c61f94e4778d632f1d8fd"
 PATCHES="patch-$portVersion.patchset"
+if [ "$effectiveTargetArchitecture" = x86_gcc2 ]; then
+PATCHES+="
+	patch-$portVersion-gcc2.patchset
+	"
+fi
 
 ARCHITECTURES="x86_gcc2 x86 x86_64 arm"
 if [ "$targetArchitecture" = x86_gcc2 ]; then

sys-devel/patch/patches/patch-2.7.6.patchset

@@ -5,7 +5,7 @@ Subject: fstatat is in sys/stat.h
 
 
 diff --git a/lib/symlinkat.c b/lib/symlinkat.c
-index ce10d94..814b19a 100644
+index 7a663af..b6b09e2 100644
 --- a/lib/symlinkat.c
 +++ b/lib/symlinkat.c
 @@ -18,6 +18,9 @@
@@ -19,5 +19,5 @@ index ce10d94..814b19a 100644
  #include <errno.h>
  
 -- 
-1.8.3.4
+2.19.1