[llvm clang] make and configure opensource

[nguyenvulong]

I tried to install apache httpd by building from source.
httpd has additional packages like apr and apr-util. APR stands for Apache Portable Runtime (APR).

I had two ways to build them
a) together, put apr and apr-util inside srclib, then ./buildconf and ./configure httpd
b) separately, ./configure apr and apr-util and httpd alone. This is only useful for debugging and inspecting bitcode (see [1]). And it kinda takes time since you have to configure each package separately. Refer to [3] for fun and #67 for fix.

Necessary packages

sudo apt update
sudo apt install libapr1-dev
sudo apt install autoconf libtool-bin
sudo apt install llvm clang
sudo apt install build-essential
sudo apt install libpcre3-dev
sudo apt install libexpat1-dev
sudo apt install cmake

[1] https://discourse.llvm.org/t/llvm-link-symbol-multiply-defined/718
[2] https://stackoverflow.com/questions/9436860/apache-httpd-setup-and-installation
[3] https://github.com/shamedgh/temporal-specialization/blob/master/COMPILE.md