Handle tilegx* machine names.

This patch makes sysdeps/tile/preconfigure handle tilegx* machine
names instead of just plain tilegx.  That matches GCC, and in
particular allows a big-endian toolchain to use the tilegxbe-linux-gnu
name when configuring both GCC and glibc.

Tested with compilation for tilegxbe-linux-gnu, both 32-bit and 64-bit
(building a subsequent GCC against that glibc still falls over because
of both 32-bit and 64-bit libraries going in the lib directory, as
noted at
<https://sourceware.org/ml/libc-alpha/2016-11/msg00129.html>).

	* sysdeps/tile/preconfigure: Accept tilegx* instead of tilegx.

ChangeLog

@@ -1,3 +1,7 @@
+2016-11-04  Joseph Myers  <joseph@codesourcery.com>
+
+	* sysdeps/tile/preconfigure: Accept tilegx* instead of tilegx.
+
 2016-11-03  Joseph Myers  <joseph@codesourcery.com>
 
 	* conform/Makefile ($(linknamespace-header-tests)): Also depend on

sysdeps/tile/preconfigure

@@ -2,7 +2,7 @@
 case "$machine" in
     tilepro)
 	base_machine=tile machine=tile/tilepro ;;
-    tilegx)
+    tilegx*)
 	base_machine=tile
 	if $CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | grep -q __LP64__; then
 	    machine=tile/tilegx/tilegx64