Add mips32 to LLVM configure's list of allowed Subzero targets

configure

 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.60 for LLVM 3.6.0svn.
 #
 # Report bugs to <http://llvm.org/bugs/>.
 #
 # Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
 # 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
 # This configure script is free software; the Free Software Foundation
 # gives unlimited permission to copy, distribute and modify it.
@@ skipping 5471 matching lines @@
 fi
 
 case "$enableval" in
   none) ;;
   *)for a_target in `echo $enableval|sed -e 's/,/ /g' ` ; do
       case "$a_target" in
         X8632)  SUBZERO_TARGETS_TO_BUILD="X8632 $SUBZERO_TARGETS_TO_BUILD" ;;
         X8664)  SUBZERO_TARGETS_TO_BUILD="X8664 $SUBZERO_TARGETS_TO_BUILD" ;;
         ARM32)  SUBZERO_TARGETS_TO_BUILD="ARM32 $SUBZERO_TARGETS_TO_BUILD" ;;
         ARM64)  SUBZERO_TARGETS_TO_BUILD="ARM64 $SUBZERO_TARGETS_TO_BUILD" ;;
+        MIPS32) SUBZERO_TARGETS_TO_BUILD="MIPS32 $SUBZERO_TARGETS_TO_BUILD" ;;
         *) { { echo "$as_me:$LINENO: error: Unrecognized subzero target $a_target" >&5
 echo "$as_me: error: Unrecognized subzero target $a_target" >&2;}
    { (exit 1); exit 1; }; } ;;
       esac
   done
   ;;
 esac
 
 SUBZERO_ENUM_TARGETS=""
 for target_to_build in $SUBZERO_TARGETS_TO_BUILD; do
@@ skipping 14553 matching lines @@
            --cache-file=\"\$ac_sub_cache_file\" --srcdir=\"\$ac_srcdir\"" ||
         { { echo "$as_me:$LINENO: error: $ac_sub_configure failed for $ac_dir" >&5
 echo "$as_me: error: $ac_sub_configure failed for $ac_dir" >&2;}
    { (exit 1); exit 1; }; }
     fi
 
     cd "$ac_popdir"
   done
 fi