patch 8.2.0213: configure does not recognize gcc 10.0 and later

Problem:    Configure does not recognize gcc 10.0 and later.
Solution:   Adjust the pattern matching the version number. (Sergei
            Trofimovich, closes #5580)

src/auto/configure

@@ -14762,7 +14762,7 @@ DEPEND_CFLAGS_FILTER=
 if test "$GCC" = yes; then
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for GCC 3 or later" >&5
 $as_echo_n "checking for GCC 3 or later... " >&6; }
-  gccmajor=`echo "$gccversion" | sed -e 's/^\([1-9]\)\..*$/\1/g'`
+  gccmajor=`echo "$gccversion" | sed -e 's/^\([0-9]\+\)\..*$/\1/g'`
   if test "$gccmajor" -gt "2"; then
     DEPEND_CFLAGS_FILTER="| sed 's+-I */+-isystem /+g'"
     { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5

src/configure.ac

@@ -2195,7 +2195,7 @@ else
   fi
 
   dnl On my HPUX system the X include dir is found, but the lib dir not.
-  dnl This is a desparate try to fix this.
+  dnl This is a desperate try to fix this.
 
   if test -d "$x_includes" && test ! -d "$x_libraries"; then
     x_libraries=`echo "$x_includes" | sed s/include/lib/`
@@ -4447,7 +4447,7 @@ dnl the number before the version number.
 DEPEND_CFLAGS_FILTER=
 if test "$GCC" = yes; then
   AC_MSG_CHECKING(for GCC 3 or later)
-  gccmajor=`echo "$gccversion" | sed -e 's/^\([[1-9]]\)\..*$/\1/g'`
+  gccmajor=`echo "$gccversion" | sed -e 's/^\([[0-9]]\+\)\..*$/\1/g'`
   if test "$gccmajor" -gt "2"; then
     DEPEND_CFLAGS_FILTER="| sed 's+-I */+-isystem /+g'"
     AC_MSG_RESULT(yes)

src/version.c

@@ -742,6 +742,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    213,
 /**/
     212,
 /**/