Bash 4.2.0(1)-release, which we use during bootstrap, does not yield the
"x" case in:

  case x"$EMULATION_NAME" in x) ;; *) ;; esac

when 'EMULATION_NAME' is undefined.  Bash 4.3.30(1)-release doesn't have this
problem.  Work around it.

This Bash bug was fixed
in <http://ftp.gnu.org/gnu/bash/bash-4.2-patches/bash42-007>.

--- a/ld/emulparams/elf32bmipn32-defs.sh
+++ b/ld/emulparams/elf32bmipn32-defs.sh
@@ -13,7 +13,7 @@ LITTLE_OUTPUT_FORMAT="elf32-littlemips"
 TEMPLATE_NAME=elf32
 EXTRA_EM_FILE=mipself
 
-case x"$EMULATION_NAME" in
+case "x$EMULATION_NAME" in
 xelf32*n32*) ELFSIZE=32 ;;
 xelf64*) ELFSIZE=64 ;;
 x) ;;