ENABLE_CHECKING in bfd, opcodes, binutils, ld

gas already has this.  Here it enables checking hash table type passed
to elf_link_hash_lookup and elf_link_hash_traverse.

bfd/
	* elf-bfd.h (ENABLE_CHECKING): Define.
	(elf_link_hash_lookup): Abort if wrong type of hash table.
	(elf_link_hash_traverse): Likewise.
	* configure.ac (--enable-checking): Add support.
	* config.in: Regenerate.
	* configure: Regenerate.
binutils/
	* configure.ac (--enable-checking): Add support.
	* config.in: Regenerate.
	* configure: Regenerate.
ld/
	* configure.ac (--enable-checking): Add support.
	* config.in: Regenerate.
	* configure: Regenerate.
opcodes/
	* configure.ac (--enable-checking): Add support.
	* config.in: Regenerate.
	* configure: Regenerate.

ld/configure

@@ -824,6 +824,7 @@ with_gnu_ld
 enable_libtool_lock
 enable_plugins
 enable_largefile
+enable_checking
 with_lib_path
 enable_targets
 enable_64_bit_bfd
@@ -1494,6 +1495,7 @@ Optional Features:
   --disable-libtool-lock  avoid locking (might break parallel builds)
   --enable-plugins        Enable support for plugins
   --disable-largefile     omit support for large files
+  --enable-checking       enable run-time checks
   --enable-targets        alternative target configurations
   --enable-64-bit-bfd     64-bit support (on hosts with narrower word sizes)
   --enable-gold[=ARG]     build gold [ARG={default,yes,no}]
@@ -11410,7 +11412,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11413 "configure"
+#line 11415 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11516,7 +11518,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11519 "configure"
+#line 11521 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -15127,6 +15129,22 @@ fi
 
 
 
+ac_checking=
+. ${srcdir}/../bfd/development.sh
+test "$development" = true && ac_checking=yes
+# Check whether --enable-checking was given.
+if test "${enable_checking+set}" = set; then :
+  enableval=$enable_checking; case "${enableval}" in
+  no|none)  ac_checking= ;;
+  *)	    ac_checking=yes ;;
+esac
+fi
+if test x$ac_checking != x ; then
+
+$as_echo "#define ENABLE_CHECKING 1" >>confdefs.h
+
+fi
+
 
 # Check whether --with-lib-path was given.
 if test "${with_lib_path+set}" = set; then :