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

configure

Index: configure
diff --git a/configure b/configure
index 3258440afcfa370eaba2fcbd2cf359a540c83ae0..bfeb9035992902ff3bec462affc56a84f866c9cd 100755
--- a/configure
+++ b/configure
@@ -5489,6 +5489,7 @@ case "$enableval" in
         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; }; } ;;