Gold: Add targ_extra_little_endian to configure.ac

This option will be used by architectures which is big endian
by default, while little-endian support is also needed.

Mips(eb) ports are the examples.

gold/configure

@@ -5266,6 +5266,10 @@ for targ in $target $canon_targets; do
 	      -o "$targ_extra_big_endian" = "true"; then
 	      targ_32_big=yes
 	  fi
+	  if test "$targ_little_endian" = "true" \
+	      -o "$targ_extra_little_endian" = "true"; then
+	      targ_32_little=yes
+	  fi
 	  if test "$targ_big_endian" = "false" \
 	      -o "$targ_extra_big_endian" = "false"; then
 	      targ_32_little=yes
@@ -5276,6 +5280,10 @@ for targ in $target $canon_targets; do
 	      -o "$targ_extra_big_endian" = "true"; then
 	      targ_64_big=yes
 	  fi
+	  if test "$targ_little_endian" = "true" \
+	      -o "$targ_extra_little_endian" = "true"; then
+	      targ_64_little=yes
+	  fi
 	  if test "$targ_big_endian" = "false" \
 	      -o "$targ_extra_big_endian" = "false"; then
 	      targ_64_little=yes

gold/configure.ac

@@ -193,6 +193,10 @@ for targ in $target $canon_targets; do
 	      -o "$targ_extra_big_endian" = "true"; then
 	      targ_32_big=yes
 	  fi
+	  if test "$targ_little_endian" = "true" \
+	      -o "$targ_extra_little_endian" = "true"; then
+	      targ_32_little=yes
+	  fi
 	  if test "$targ_big_endian" = "false" \
 	      -o "$targ_extra_big_endian" = "false"; then
 	      targ_32_little=yes
@@ -203,6 +207,10 @@ for targ in $target $canon_targets; do
 	      -o "$targ_extra_big_endian" = "true"; then
 	      targ_64_big=yes
 	  fi
+	  if test "$targ_little_endian" = "true" \
+	      -o "$targ_extra_little_endian" = "true"; then
+	      targ_64_little=yes
+	  fi
 	  if test "$targ_big_endian" = "false" \
 	      -o "$targ_extra_big_endian" = "false"; then
 	      targ_64_little=yes

gold/configure.tgt

@@ -165,7 +165,7 @@ mips*-*-*)
  targ_machine=EM_MIPS
  targ_size=32
  targ_big_endian=true
- targ_extra_big_endian=false
+ targ_extra_little_endian=true
  ;;
 s390-*-*)
  targ_obj=s390