Permission denied when running make install
Solution 1:
It seems like it's trying to execute a file /home/harshilsharma63/llvm/autoconf/mkinstalldirs but it doesn't have the permission to do this.
Just try to make this file runnable:
sudo chmod a+x /home/harshilsharma63/llvm/autoconf/mkinstalldirs
Then try to clean the make and do it again:
sudo make clean
./configure
make
sudo make install
Solution 2:
You could try chmod a+rx /home/harshilsharma63/llvm/autoconf/mkinstalldirs