tests: add a script to build bitmanip test

tests/bitmanip/run.sh

+#!/bin/bash
+
+# This script builds the bitmanip tests.  You should input the num of tests
+
+if [ $# -ne 2 ]; then
+    echo "Usage: $0 <num of cases in bitmanip> <num of tests>"
+    echo "Example: $0 10000 10"
+    exit 1
+fi
+
+for i in `seq 1 $2`
+do
+    cd src
+    rm *.S
+    python3 randtest.py $1 1
+    cd ..
+    make ARCH=riscv64-xs
+    mv build/bitmanip-riscv64-xs.bin build/bitmanip-riscv64-xs-$i.bin
+    mv build/bitmanip-riscv64-xs.elf build/bitmanip-riscv64-xs-$i.elf
+done